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CONCRETE FACE ROCKFILL DAMS

CONCEPTS FOR DESIGN AND CONSTRUCTION

ICOLD

COMMITTEE ON MATERIALS FOR FILL DAMS

July 2005

DRAFT

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TABLE OF CONTENTS

Preface .............................................................................................................. vii 1. Development of the Concrete Face Rockfill Dam .................................................1-1 1.1 Typical Current Section of the CFRD .........................................................1-2 1.2 Summary of 1965-2002 Progress To Current Practice .................................1-4 1.3 Features of The CFRD ................................................................................1-6 1.4 Evaluation of Leakage Performance............................................................1-7 1.5 References ..................................................................................................1-9 2. Analyses for Design ................................................................................................2-1 2.1 Static Stability of the CFRD........................................................................2-1 2.2 Dynamic Stability of the CFRD ..................................................................2-3 2.3 Settlement and Compression..................................................................... 2-11 2.4 Estimating Face Slab Deformation............................................................ 2-15 2.5 Estimating Seepage Through The Foundation And The Slab..................... 2-17 2.6 References ................................................................................................ 2-17

3. Foundation Excavation and Treatment.................................................................3-1 3.1 Foundation Treatment Objectives ...............................................................3-1 3.2 Plinth Foundation Treatment.......................................................................3-1 3.3 Embankment Foundation Treatment ...........................................................3-9 3.4 Consolidation and Curtain Grouting.......................................................... 3-10 3.5 References ................................................................................................ 3-13 4. Plinth .............................................................................................................4-1 4.1 Dimensions of the Plinth.............................................................................4-1 4.2 Geometry Downstream of the Plinth ...........................................................4-5 4.3 Geometric Layout of the Plinth ...................................................................4-6 4.4 Stability of the Plinth ..................................................................................4-9 4.5 Reinforcement, Waterstops, and Anchors.................................................. 4-11 4.6 References ................................................................................................ 4-11 5. Perimeter Joints and Waterstops ..........................................................................5-1 5.1 Introduction ................................................................................................5-1 5.2 Perimeter Joint Designs ..............................................................................5-3 5.3 Lower Water Barrier ...................................................................................5-6 5.4 Middle Water Barrier ..................................................................................5-8 5.5 Upper Water Barrier ...................................................................................5-9 5.6 Additional Perimeter Joint Details............................................................. 5-13 5.7 References ................................................................................................ 5-13



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6. Face slab ............................................................................................................6-1 6.1 Behavior of Face Slabs ...............................................................................6-1 6.2 Face Slab Dimensions.................................................................................6-2 6.3 Crack Development in Face Slabs...............................................................6-6 6.4 Concrete Properties.....................................................................................6-8 6.5 Reinforcing.................................................................................................6-9 6.6 References ................................................................................................ 6-11 7. Parapet wall ...........................................................................................................7-1 7.1 Introduction ................................................................................................7-1 7.2 Height of Wall ............................................................................................7-1 7.3 Joint between Wall and Face Slab...............................................................7-2 7.4 Transverse Joints ........................................................................................7-3 7.5 Abutment Details ........................................................................................7-3 7.6 Crest Width ................................................................................................7-3 7.7 Case Histories.............................................................................................7-3 7.8 References ..................................................................................................7-6 8. Embankment Zones and Properties ......................................................................8-1 8.1 Zoning of the CFRD ...................................................................................8-1 8.2 Filter (Zone 2A) .........................................................................................8-3 8.3 Face Slab Support Material (Zone 2B) ..................................................... 8-10 8.4 Body of Dam (Zones 3A, 3B, and 3C) ...................................................... 8-16 8.5 Drainage (Zone 3D) .................................................................................. 8-17 8.6 References ............................................................................................... 8-18 9. Instrumentation .....................................................................................................9-1 9.1 Introduction ................................................................................................9-1 9.2 Limitations .................................................................................................9-2 9.3 Instrumentation Systems .............................................................................9-2 9.4 Case Histories.............................................................................................9-6 9.5 References ..................................................................................................9-9 10. Performance of CFRDs ...................................................................................... 10-1 10.1 Moduli of Deformation ........................................................................... 10-1 10.2 Perimeter Joint Movement ..................................................................... 10-1 10.3 Post-Construction Crest Settlement ........................................................ 10-1 10.4 Leakage and Remedial Treatment .......................................................... 10-2 10.5 References ............................................................................................ 10-16 11. Appurtenant Structures .................................................................................... 11-1 11.1 Low level outlet ..................................................................................... 11-1 11.2 Connection to Spillway and Intake Walls ................................................ 11-2 11.3 Spillways over the dam........................................................................... 11-3 11.4 References .............................................................................................. 11-4



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Appendix Partial list of CFRDs with basic data, current as of April, 2001



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PREFACE

Bulletin 70, Rockfill Dams with Concrete Facing, was published in 1989. The Bulletin was authored by Jorge E. Hacelas and Alberto Marulanda on behalf of the Colombian Committee on Large Dams for the ICOLD Committee on Materials for Fill Dams. In addition to Bulletin 70, the following were the main sources for this update:

• Proceedings, Concrete Face Rockfill Dams, Design, Construction, and Performance, ASCE, Detroit, October 1985.

• Proceedings, International Symposium on High Earth-Rockfill Dams-Especially CFRD, Beijing, October 1993.

• Proceedings, Second Symposium on Concrete Face Rockfill Dams, Brazilian Committee on Dams, Florianopolis, Brazil, October, 1999.

• CFRD 2000, Proceedings, International Symposium on Concrete Faced Rockfill Dams, Beijing, September 2000.

• J. Barry Cooke Volume, Concrete Face Rockfill Dams, Beijing, September 2000. Following the 1985 symposium in Detroit, USA, and during the decade of the 1990s, the concrete face rockfill dam has become common. A cursory review of the listing of CFRDs in the appendix indicates the widespread use and popularity of this type of dam. The updated Bulletin contains eleven chapters devoted to design concepts, analysis, foundation treatment, instrumentation, construction, and performance. The work of the following authors is acknowledged: Chapters 1, 2, 3, 4, 8, and 10: David E. Kleiner Chapters 5 and 6: Jason E. Hedien Chapters 7 and 9: Archie V. Sundaram and David E. Kleiner Chapter 11: Carlos Jaramillo Appendix J. Barry Cooke, Bayardo Materon The Chairman, Alberto Marulanda, provided detailed review and many contributions to all chapters that added significantly to the bulletin. Alberto Marulanda, Chairman Committee on Materials for Fill Dams



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Chapter 1 DEVELOPMENT OF THE CONCRETE FACE ROCKFILL DAM The concrete face rockfill dam, CFRD, had its origin in the mining region of the Sierra Nevada in California in the 1850s. Experience up to 1960 using dumped rockfill, demonstrated the CFRD to be a safe and economical type of dam, but subject to concrete face damage and leakage caused by the high compressibility of the segregated dumped rockfill. As a result, the CFRD became unpopular, although rockfill had been demonstrated to be a high strength and economical dam building material. Partly in response to these problems, the earth core rockfill dam, with compressible dumped rockfill, was developed. The dumped rockfill was found to be compatible with the earth core and its filters. With the advent of vibratory-roller-compacted rockfill in the 1950s, the development of the CFRD resumed. Although design is largely based on precedent, there has been continuous progress in design aspects and in construction methods. Today, the CFRD is again a major dam type. Figure 1-1 illustrates the trends in the height of the CFRD up to the year 2000.

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40

01900 1925 1930 1940 1950 1960 1970 1980 1990

E A R L Y P E R I O D M O D E R N P E R I O DT R A N S I T I O N P E R I O D

2000

A

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13

98 107

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5

4

32

1

Heigh

t (m

)

Legend: • Dumped Rockfill o Compacted Rockfill

1 Strawberry Creek 2 Salt Springs 3 Paradela 4 Quioch 5 New Exchequer 6 Cethana 7 Anchicaya 8 Areia 9 Khao Laem 10 Segredo 11 Aguamilpa 12 Yacambu 13 Tianshenqiao A 68 CFRDs completed between 1990 and 2000, height 40 to 120 m

Figure 1-1 Trends in the Height of the CFRD with Time (Cooke, 1997, extended to 2000)



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Several CFRDs, 140 m high or higher, completed or under construction since the year 2000 include:

• Antamina, Peru, 140 m high, completed in 2001. • Mohale, Lesotho, 145 m high, completed in 2002. • *Campos Novos, Brazil, 202 m high, under construction, 2003. • *Barra Grande, Brazil, 140 m high, under construction, 2003. • *Karahnjukar, Iceland, 190 m high, under construction, 2003. • *Bakun, Sarawak, Malaysia, 205 m high, under construction, 2003.

* Data source, Hydropower & Dams, 2003.

1.1 Typical Current Section of the CFRD

Figure 1-2 is a schematic section of the CFRD consisting of sound compacted rockfill founded on a sound rock foundation. Outer slopes can be as steep as 1.3H:1V. For a weaker rockfill and foundation, upstream and downstream slopes, zoning, drainage and construction are adapted to accommodate the weak rock. For a potentially erodible foundation, additional sealing and filter provisions are constructed downstream of the plinth. The zone designations of 1, 2, and 3 have become the standard, Cooke, 1991, 1997: • Zones 1A, 1B – concrete face protection (upstream) zones, in increasing order of maximum

particle size, • Zones 2A, 2B – concrete face supporting (downstream) zones, in increasing order of maximum

particle size, these are processed granular materials, and • Zones 3A, 3B, etc. – rockfill zones, in increasing order of maximum particle size. Zone 1B provides support for Zone 1A and in some cases also resists uplift of the face slab prior to reservoir filling. Zone 1A, a cohesionless silt or fine sand, is placed to a higher elevation on high dams so that it can act as a joint or crack healer over the perimeter joint and the lower part of the face slab. Compaction of Zones 1A and of the random Zone 1B is by hauling and spreading equipment. Zone 2A is a processed fine filter with specific gradation limits, minus 20 mm or minus 12 mm. It is to limit leakage in the event of waterstop failure and to self heal with underwater placement of silt or silty fine sand. Zone 2B, the face support zone, has often been specified as crusher run minus 75 mm sound rock material. Alternatively, specific gradation limits are specified. The zones 2A and 2B, their gradation, placement and protection during construction, have received considerable attention recently. A detailed discussion of these materials is contained in Chapter 8, Fill Materials.



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Figure 1-2. Zones for CFRD of sound rock on sound rock foundation (adapted from Cooke, 1991, 1997)

Zone 3 is quarry run rockfill. The differences in A, B and C are principally in layer thickness and size and type of rock. Zone 3A is to provide compatibility and limit void size adjacent to Zone 2B. Zone



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3B resists the water loading and limits face deflection. Zone 3C receives little water loading, and settlement is essentially during construction. The thicker layer in Zone 3C accepts larger rock, is more economical to place, and its lower density (about 5% less than Zone 3B density) saves rock volume. Large rock is often placed at the downstream toe to resist scour and tailwater wave action. The typical section is shown for rockfill. Gravel, when available in adequate quantity, can be more economical even with the necessary flatter slopes. Its higher modulus is desirable but not always necessary. The layer thicknesses for Zones 3B and 3C of gravel are thinner, on the order of 0.6 m and 1.2 m respectively.

.5M

.5M

TopAverageBottom

2.12.01.9

2.22.12.0

2.252.152.05

A B C

TEST PIT DENSITY (SP. GR.=2.65)

2-3 m ring

Figure 1-3. Placement and section of compacted rockfill (Cooke, 1991, 1997) Figure 1-3 illustrates a layer of compacted rock. The rockfill is end dumped on the edge of the layer being placed and spread by the dozer. There is inherent segregation in the dumping and intentional segregation in the spreading. The smooth surface of fines on top of the layer is desirable for compaction and for reduced tire and dozer track costs. The top half consists of smaller size rock and is well graded in comparison to the larger rocks in the bottom half. The upper half is of higher density. Energy is transmitted through the larger rocks providing strength and density by wedging and crushing of edges. A method specification is used; density tests are sometimes taken for the record. The A, B and C density designations in the figure are respectively for poorly, average and well graded quarry run rock placed in 1 m layers and compacted by four passes of the 10 static ton vibratory roller. All the densities are satisfactory depending on the specific gravity of the rock and the void ratio of the fill. Low void ratios are desirable and lead to the least settlement within the fill. The maximum size rock in a layer may be equal to the layer thickness. Immediately adjacent rockfill will not be fully compacted and does not need to be. The larger rock particles will attract load in the area.

1.2 Summary Of 1965-2000 Progress To Current Practice During the 1965-2000-development period, many CFRDs were adopted to replace a previously selected arch, gravity or earth-core-rockfill dam type. Reasons for the change to the CFRD included



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the late discovery of adverse foundation conditions for a concrete dam, cost, or lack of appropriate core material for an earth-core-rockfill dam. Today, the CFRD is an established major dam type to be included in initial project feasibility studies. A summary of progress and current practice is: 1. Precedent maximum heights have jumped from 90 to 187 m. Maximum heights under

construction or planned exceed 200 m. 2. The reinforced concrete plinth anchored to the foundation, first used at Exchequer and Cabin

Creek, has since become standard practice. Up to about 1958, standard practice for the connection of the concrete face with the rock foundation was a concrete cutoff as described by Cooke, 1960, with examples of Salt Spring Dam, Lower Bear River Dam and Wishon Dam. This practice changed dramatically after Terzaghi, 1960, provided a discussion of the Cooke paper. After stating that the cutoff serves only the purpose of reducing the seepage losses to a tolerable value, he proposed that the most economical procedure for intercepting the flow of seepage would be to eliminate the concrete cutoff, and replace it by a plinth anchored to the foundation, and to grout the rock beneath the slab. His final remarks are appropriate: “it is rather difficult to understand how the brutal practice of blasting a cutoff trench out of sound rock came into existence. It may be the vestige of the days when the technique of rock grouting was still unknown”.

3. Foundation treatment below and downstream of the plinth always receives close attention. 4. Gravel is used in the dam cross section whenever economically available. 5. When rockfill is not positively free draining, liberal provision is made for internal drainage. 6. Face zones of highly pervious, semi-pervious and impervious material have all been satisfactory.

Current practice of crusher-run minus 50 or 75 mm rock, obtained from a sound, competent source, is satisfactory, economical and practical.

7. Plate vibrator compaction within 3 m of the perimeter joint on the horizontal and sloped surface is

now required. The vibratory roller cannot get close enough to adequately compact this zone, and poor compaction has been a cause of excessive offset and of waterstop damage. Many modern dams now use the “curb” method to provide face protection during construction and the ability to achieve good compaction of Zones 2A and 2B. Use of the curb eliminates the need for plate vibrator compaction (Resende and Materon, 2000).

8. A fine filter, minus 20 or 12 mm, is specified within 1 to 3 m of the perimeter joint, the location

where leakage incidents have occurred. It limits leakage and allows sealing by silt or silty fine sand, a non-cohesive material.

9. Face slab thickness has been reduced from 0.3 + 0.0067 H to 0.3 + 0.002 H in meters, or is a

constant 0.3 meters for dams of moderate height.



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10. Reinforcing has been reduced from 0.5% each way to 0.3% horizontal and 0.35 or 0.4% vertical

and near the abutments. 11. Experience, with partial filling due to extreme floods before the concrete face has been placed,

has demonstrated the ability of rockfill to accept high leakage safely. Rockfill is an effective energy dissipater.

1.3 Features Of The CFRD The CFRD dam has many attractive features in design, construction, and schedule. Design Features. 1. All of the zoned rockfill is downstream from the water barrier. The sliding factor of safety often

exceeds 7. The dam supports the abutments. 2. A plinth with appropriate foundation treatment below, upstream and/or downstream, connects the

water barrier (concrete face slab) to the foundation. A parapet wall at the crest provides a wider surface for construction of the face slab and reduces the volume of rockfill.

3. Uplift is not an issue. The pressure on the foundation exceeds reservoir pressure over three-

quarters of the base width. 4. Water load is transmitted into the foundation upstream from the dam axis, an inherently safe

feature. 5. Since all of the rockfill is dry, earthquake shaking cannot cause internal pore water pressure. 6. The conditions of high shear strength, no pore pressure, and small settlement under seismic

loading make the zoned rockfill inherently resistant to seismic loading. 7. The only credible mechanism of failure of a CFRD founded on rock is erosion by sustained

overtopping flow. Hydrology, spillway, and freeboard design is the response to this risk. Piping of the foundation is a potential mode of failure as a result of the increasing use of CFRDs on weathered rock and alluvial foundations.

8. Post construction movements are small, and cease after several years. 9. Surveillance by monitoring surface movement and measuring leakage is required, as for any dam,

but little or no instrumentation is needed for safety monitoring.



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Construction and Schedule Features. 1. Ramps are permitted within the body of the dam in any direction. This minimizes haul roads to

the dam and facilitates traffic and placement on the dam. Inappropriate construction of ramps, delay in placement of rockfill within the downstream shoulder of the dam to accommodate staging, and haul roads that cross the plinth leaving holes to be filled later, can cause irregular settlement of the dam and can lead to cracking of the concrete face prior to and subsequent to reservoir filling.

2. Where site conditions permit, rockfill may be placed on abutments prior to river diversion. This

allows required excavations to be placed directly into the dam. On major rivers, early placement of rockfill on abutments decreases the volume of rockfill in the closure section, thus reducing or eliminating overtopping risk during construction.

3. CFRDs allow great flexibility for the management of the river during construction. Their natural

strength to overtopping, combined with special design features, such as, reinforced rockfill in the downstream face, and RCC cofferdams, allow the use of lower interval recurrence floods and still have an equivalent risk exposure during the construction period to other types of embankment dams.

4. The plinth construction and grouting are outside the dam and do not interfere with embankment placement or the construction schedule.

5. Rockfill placement is relatively unrestricted and not affected by rainfall. Scheduling is reliable.

6. The slip forming of the concrete face is a repetitive planned procedure that can be reliably scheduled.

7. The concrete face can be constructed in stages at the convenience of the Contractor. Too many stages and delay in placement of rockfill in the downstream shoulder of the dam can cause adverse settlement that can affect the performance of the concrete face slab prior to and subsequent to reservoir filling.

8. The plinth and internal slab can be constructed by slipforming simplifying construction. 9. The parapet wall located at the crest of the dam can be constructed of precast elements, thus

improving schedule. 10. The use of the upstream extruded curb have reduced segregation of the transition 2B and

eliminating upstream slope compaction (Resende and Materon, 2000).

1.4 Evaluation of Leakage Performance

The leakage performance of the CFRD has recently been criticized in the professional literature (Anthiniac, et al, 2002). Four case histories were studied and evaluated using numerical analysis:



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Aguamilpa, Mexico, 187 m high; Xingo, Brazil, 140 m high; Tianshengqiao 1, China, 180 m high; and Ita, Brazil, 125 m high. Based on the analysis of these four dams, the authors state:

“Yet the first impounding of CFRDs is all too often accompanied by leakage, sometimes on an impressive scale, which disturbs the operation of the schemes, diminishes their profitability, and requires costly remedial measures, the efficiency of which can be uncertain. The owners of such dams are disenchanted and wrongly believe that leakage is an inherent flaw of CFRDs.” (Anthiniac, et al, 2002). “The safety of the dams was never called into question, since the materials of which they are made enable water to flow out freely without causing any damage, but the leakage rates were deemed to be too high, given the type of dam and the functions involved. Moreover, the current trend is to accept increasingly high leakage rates, implying that leakage is not a danger.” (Anthiniac, et al, 2002).

The authors suggest several causes for the high leakage rates. Particular design details and/or construction defects lead to larger absolute and differential deformations of the face slab, which can then lead to face slab cracking. Avoiding these causes by means of appropriate selection of filter and rockfill materials, upstream and downstream shell placement in thinner layers along with generous use of water during compaction, elimination of rock protrusions downstream of the perimeter joint, and avoiding inappropriate shell construction sequences, will lead to smaller deformations and a reduction in face slab cracking. One of the purposes of this Bulletin is to emphasize that careful selection of design and construction details is extremely important to avoid face cracking and embarrassing leakage rates.

It is certainly not the position of this Bulletin or of ICOLD “to accept increasingly high leakage rates” in CFRDs. Many modern CFRDs, designed and constructed in recent years, have performed extremely well with respect to leakage rates (see Chapter 11, Performance). As an example, the recently completed Antamina CFRD in Peru, 140 m high, had a leakage rate of less than one liter per second upon completion of reservoir filling. High leakage rates, even if safety is not jeopardized, are embarrassing to the engineer, the constructor and the owner and are to be avoided to the maximum extent possible. 1.5 References Anthiniac, P., Carrere, A., Develay, D., Andrzejewski, R. H., “The Contribution of Numerical

Analysis to the Design of CFRDs”, Hydropower & Dams, Issue Four, page 127-132, 2002. Cooke, J. B., “Wishon and Courtright Concrete Face Dams”, by J. Barry Cooke, Symposium on

Rockfill Dams, Transactions ASCE, Vol. 125, Part II, 1960. Cooke, J. B., “Progress in Rockfill Dams (18th Terzaghi Lecture)”, Journal of Geotechnical

Engineering, ASCE, v.110, No. 10, p.1383-1414, 1984.



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Cooke, J. B. and Sherard, J. L., editors, “Concrete Face Rockfill Dams - Design, Construction and Performance”, Proceedings, Symposium sponsored by the Geotechnical Engineering Division, ASCE, Detroit, Michigan, 658 pages, 1985.

Cooke, J. B., “Progress in Rockfill Dams, Discussions and Closure”, Discussions by: R. Casinader,

W. L. Chadwick, C. A. Fetzer, M. D. Fitzpatrick, E. M. Fucik, Jorge E. Hacelas and Carlo A. Ramirez, A. C. Houslby, A. Maralunda and C. S. Ospina, Bayardo Materon, A. H. Merritt, N. G. K. Murti, Ivor L. Pinkerton, Pietro De Porcellinis, C.F. Ripley, James L. Sherard, Arthur G. Strussburger, William F. Swiger, H. Taylor, and author closure, Journal of Geotechnical Engineering, ASCE, v.112, No. 2, p. 217-253, 1986.

Cooke, J. B., “The Concrete-faced Rockfill Dam”, Water Power & Dam Construction, January 1991. Cooke, J. B. and Sundaram, A. V., “Section 16, Concrete Face Rockfill Dams”, Davis’ Handbook of

Applied Hydraulics”, 4th edition, Zipparro, V. J. and Hasen, H. editors, McGraw-Hill, New York, 1992.

Cooke, J. B., “The Concrete Face Rockfill Dam”, Non-Soil Water Barriers for Embankment Dams,

17th Annual USCOLD Lecture Series, San Diego, CA, pp 117-132, April, 1997. Hydropower & Dams, “Progress at Current Major CFRD Projects”, Issue Four, pp. 79-87, 2003. ICOLD, “Rockfill Dams with Concrete Facing-State of the Art”, International Commission on Large

Dams, Bulletin 70, 1989. Kollgaard, E. B., and Chadwick, W. L., editors, “Development of Dam Engineering in the United

States”, prepared in commemoration of the 16th ICOLD Congress, United States Committee on Large Dams, New York, Pergamon Press, 1072 p, 1988.

Li Eding, (China) Chairman, International Symposium on High Earth-Rockfill Dams-Especially

CFRDs, Proceedings, Beijing, China, 3 Volumes (English), October 26-29, 1993. Resende. F., Materon, B., “Ita Method—New Construction Technology for the Transition Zone of

CFRDs”, CFRD 2000, Proceedings, International Symposium on Concrete Faced Rockfill Dams, 18 September 2000, Beijing, China.

Sherard, J. L., “Concrete-face rockfill dam (CFRD)”, Special Memorial Issue, Journal of

Geotechnical Engineering, ASCE, v.113, No. 10, p.1095-1201, 1987. “Assessment”, paper No. 21852, Sherard, J. L. and Cooke, J. B. “Design”, paper No. 21853, Cooke, J. B. and Sherard, J. L. Discussions on 1985 Symposium papers. Closure by Cooke, J. B. Journal of Geotechnical Engineering, ASCE, v 115, No. 3, p.431-433, 1989.



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Steele, I.C. and Cooke, J.B., “Section 19, Concrete Face Rockfill Dams”, Davis’ Handbook of Applied Hydraulics”, 3rd edition, Davis, C.V., and Sorenson, K.E. editors, McGraw-Hill, New York, 1969.

Terzaghi, K., Discussion on “Wishon and Courtright Concrete Face Dams”, by J. Barry Cooke,

Symposium on Rockfill Dams, Transactions ASCE, Vol. 125, Part II, 1960. Terzaghi Lectures, 1974-1982, Geotech Special Publication No. 1. Water Power & Dam Construction, Volume 43, Number 1, January 1991; Volume 44, Number 4,

April 1992; Volume 45, Number 2, February 1993; Volume 51, Number 3, March 1999.



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Chapter 2

ANALYSES FOR DESIGN Although few analyses are required for the design of the CFRD, several analyses are suggested to provide the engineer and owner with information upon which to judge the performance of the dam throughout the life of the project from construction, first reservoir filling, and normal project operation. Estimates of performance during an extreme event, such as an earthquake or major flood are useful for comparison in the aftermath of such an event. Most design details are developed based on precedent and on an understanding of the foundation conditions and the construction materials to be used in the dam. This chapter summarizes several simplified analyses that can be performed to evaluate static and dynamic stability, settlement and displacement, and leakage. This chapter also summarizes the performance of several rockfill dams that have successfully survived major earthquakes. In addition, a case history of the design analyses and anticipated response of a 200-m tall CFRD to static and seismic loading is presented. Both empirical techniques and the finite element method (FEM) were used to estimate the response and performance of the dam.

2.1 Static Stability of the CFRD Shear Strength of Compacted Rockfill Leps (1970) reviewed the shear strength of compacted rockfill and gravel fill as measured with the use of large diameter laboratory triaxial tests. The summary plot of the data, as presented in the paper, is shown on Figure 2-1. The shear strength, measured by the angle of internal friction, is plotted against the normal stress on the failure plane. Note that shear strength includes no apparent cohesion. The data clearly indicates the variation of shear strength with normal pressure. In general, Leps found that: • At normal stress below about 70 kPa (10 psi), the angle of internal friction varies from about

450 for low density, poorly graded weak particles to as high as 600 for high density, well graded strong particles. Leps defined weak particles as rock having an unconfined compressive strength of 3.4 to 17.2 MPa (500 to 2500 psi) and strong particles as rock having an unconfined compressive strength of 69 to 207 MPa (10,000 to 30,000 psi).

• Friction angles reduce by 60 or 70 per 10 times increase in the normal pressure on the failure

plane. • Well graded materials exhibit higher shear strength than poorly graded materials. • Higher density materials exhibit higher shear strength than low density materials.



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• Angular materials exhibit higher shear strength than rounded materials, other factors being equal.

• Dry materials exhibit higher shear strength than saturated materials Data from other rockfill and gravel fill dams generally support the findings reported by Leps, as presented in ICOLD Bulletin, 92, “Rock Materials of Rockfill Dams”.

70

65

60

55

50

45

40

35

30

Frict

ion

angl

e , i

n de

gree

sφ

Normal pressure , in pounds per square inch σN

1 2 5 10 20 10050 200 500

Infiernillo diorite 8 in. CFE 1965Infiernillo conglom 8 in. CFE 1965Malpaso conglom 8 in. CFE 1965Pinzandaran gravel 8 in CFE 1965Infiernillo basalt 7 in. CFE 1966Infiernillo gness X 7 in. CFE 1966Infiernillo gneiss Y 7 in. CFE 1966Contreras gravel 7 in. CFE 1965Santa Fe rock 7 in CFE 1965Fort Peck sand No. 20 TML 1939Scituate sand No. 8 TML 1941Ottawa std. sand – TML 1938

Isabella granite 4 in. USED 1948Cachuma gravel 3/4 in. USBR 1953Cachuma gravel 3 in. USBR 1953Cachuma quarry 3 in. USBR 1955Oroville tailings 3 in. USED 1963Soledad gravel 4 in. CFE 1965

Figure 2-1 Shear Strength of Rockfill from Large Triaxial Tests (Leps, 1970) Various studies of the shear strength of rockfill (Marsal 1973, Barton and Kjaernlsi 1981, Charles and Watts 1980, ICOLD 1993, and others) confirmed that the actual behavior of rockfill is non linear, and that a relation between the shear stress and the normal stress is of the form:

τ = A*(σ’)b where:

τ = shear strength, σ’ = effective normal stress, A, b = empirical coefficients that depend on the type of rock.



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Infinite Slope Stability Analysis A simple infinite slope stability analysis using a friction angle of 500 and a 1.3H:1V slope yields a factor of safety of 1.55, satisfactory for well compacted rockfill. Slopes as steep as 1.2H:1V have been used on the downstream slope between access road berms on some CFRDs. Because modern compaction equipment can easily and routinely create a dense, high strength fill, outer slopes of the CFRD are selected based on: • The height of the dam. Somewhat flatter slopes are selected for dams exceeding 120 m.

• The quality of the rockfill. Flatter slopes are selected when poorer quality rock is used.

• The seismicity of the region in which the CFRD is to be constructed. Flatter slopes are selected when the project is located in a region with strong seismicity.

Simple Limiting Equilibrium Stability Analyses Figure 2-2 presents the results of limiting equilibrium analysis performed at the crest of a 200-m tall CFRD. The parapet wall is 7 m tall, outer slopes are 1.5H:1V, and freeboard above the maximum operating pool is 15 m. The analysis was performed to provide input to an estimate of the performance of the dam during the maximum design earthquake, assumed equal to the maximum credible earthquake. The analysis conservatively used an angle of internal friction equal to 400. Factors of safety between 2.1 and 2.2 were calculated. Computed factors of safety, using friction angles of 45 to 500, would yield substantially higher factors of safety. Relatively high static factors of safety can be anticipated when performing slope stability analysis of the CFRD. This is partly the result of the high frictional shear strength that is present and partly the result of the absence of saturation and internal pore water pressure. Limiting equilibrium stability analyses, with and without seismic effects, are also required of potential failure surfaces passing through both the embankment and foundations, where the foundation contains weak seams (Casinader and Stapledon, 1979, Gosschalk and Kulasinghe, 1985).

2.2 Dynamic Stability of the CFRD Measured Performance of Rockfill Dams During Earthquake Table 2-1 presents the measured earthquake induced deformation of rockfill dams. The data was compiled by Swaisgood and presented at the May 1995, western regional conference of the Association of State Dam Safety Officials. Relative settlement is the measured crest settlement of the dam divided by the combined height of the dam plus any underlying alluvium expressed as percent. The Earthquake Severity Index was added to the Swaisgood table based on the estimated and recorded peak ground accelerations that occurred at the dam site.



2-4

EL. 294EL. 295

EL. 288

5.0 5.0

1 11.5 1.5

Trial failure surface,upstream factor of safety = 2.2ky =0.39 Trial failure surface,

downstream factor of safety = 2.1ky =0.39

Normal, max. water level 280

Face slab

Figure 2-2, Limit Equilibrium Analysis at Crest of CFRD

TABLE 2.1

EARTHQUAKE INDUCED DEFORMATION OF ROCKFILL DAMS

Earthquake RelativeCrest Severity Set'mentSet'mentPGA, gMagnitudeYearName of EarthquakeAT, mDH, mDam typeLocationName of Dam

Index%cm

7.860.4437.80.207.91943Illapei0.085.4CFRDChileCogoti6.070.2432.90.138.11985Mich.-Guerrero75.360.1ECRDMexicoLa Villita

19.010.2427.70.587.71990Philippines0.0114.3ECRDPhilippinesPantabangan19.010.2020.10.587.71990Philippines0.0102.1ECRDPhilippinesAya

4.580.198.80.436.71994Northridge0.047.3ECRDCaliforniaLos Angeles6.940.1615.00.576.81984Naganoken0.095.0ECRDJapanMakio1.920.1411.90.336.31987Edgecumbe?86.0ECRDNew ZealandMatahina

12.450.116.70.387.71990Philippines0.060.1ECRDPhilippinesDiayo2.620.115.80.087.71983Nihonkai-Chubu0.052.1ECRDJapanNamioka1.980.1114.30.097.31981Playa Azul75.360.1ECRDMexicoLa Villita2.160.096.10.087.51964Nigata?67.1CFRDJapanMinase1.080.0912.20.047.51985n/a75.360.1ECRDMexicoLa Villita3.570.0913.10.127.61979n/a0.0146.0ECRDMexicoEl Infiernillo4.470.093.00.426.71994Northridge0.035.7ECRDCaliforniaNorth Dike (LA)6.070.0811.00.138.11985Mich.-Guerrero0.0146.0ECRDMexicoEl Infiernillo4.570.073.70.267.11989Loma Prieta14.039.9ECRDCaliforniaSan Justo

12.450.064.30.387.71990Philippines0.070.1ECRDPhilippinesCanili4.570.064.30.267.11989Loma Prieta0.071.6ECRDCaliforniaLeroy Anderson1.010.054.30.465.81991Sierra Madre0.081.1CFRDCaliforniaCogswell1.100.046.40.057.31981Playa Azul0.0146.0ECRDMexicoEl Infiernillo3.730.042.10.276.91987Chiba-Toh?52.1ECRDJapanNagara0.600.034.60.027.61979n/a75.360.1ECRDMexicoLa Villita0.080.034.00.165.31976n/a?131.4ECRDTaiwanTsengwen1.060.032.10.106.71994Northridge0.081.1CFRDCaliforniaCogswell0.220.033.70.085.91975n/a0.0146.0ECRDMexicoEl Infiernillo2.010.021.50.416.21984Morgan Hill0.071.6ECRDCaliforniaLeroy Anderson2.340.022.70.157.01961Kitamino0.0129.9ECRDJapanMiboro0.790.022.40.047.21975n/a75.360.1ECRDMexicoLa Villita1.770.022.40.097.21975n/a0.0146.0ECRDMexicoEl Infiernillo1.640.010.60.057.71990Philippines0.0100.0ECRDPhilippinesMagat0.270.000.90.105.91975Oroville0.0234.8ECRDCaliforniaOroville

Legend:

Height of dam in mDHThickness of alluvium below the dam in mATEarth core rockfill damECRDConcrete face rockfill damCFRDPeak ground accelerationPGACrest settlement divided by the combined dam height and thickness of alluvium, in %Relative Settlement

Earthquake PGA * (Earthquake Magnitude - 4.5)^3 Severity Index



2-5

The Earthquake Severity Index, introduced by Bureau, 1985, is defined as follows: ESI = PGA*(M - 4.5)3 where: ESI = Earthquake Severity Index PGA = Peak horizontal ground acceleration at the site M = Earthquake Magnitude As shown on Figure 2-3, a rough relationship exists between the Relative Settlement and the Earthquake Severity Index.

PERFORMANCE DURING EARTHQUAKE--ROCKFILL DAMS

0.001

0.01

0.1

1

0.01 0.1 1 10 100

Earthquake Severity Index

Rel

ativ

e Se

ttlem

ent o

f Cre

st, %

Figure 2-3

In general, both types of rockfill dams, those with earth cores (ECRD) and those with a concrete face (CFRD), have performed well during large earthquakes. A major difference between these dam types is that the upstream shell of the ECRD is saturated by the reservoir, whereas in the CFRD, no portion of the embankment is saturated. Except for the potential of cracks in the concrete face or in the parapet wall, the performance of the CFRD during earthquake is anticipated to be as good as the ECRD. There are only a few records of the performance of CFRDs during and subsequent to an earthquake. Table 2-1 presents data for three CFRDs: Minase in Japan, Cogoti in Chile and Cogswell in California.



2-6

Minase Dam. In June, 1964, Minase Dam was shaken by the Niigata Earthquake (M 7.5, 147 km epicentral distance from the dam, 750 mm/s2 estimated peak ground acceleration at the dam). As a result of this earthquake, the crest settled about 150 mm and displaced horizontally about 100 mm. The earthquake temporarily increased leakage from about 100 l/s to somewhat over 200 l/s. Within a few days, leakage returned to pre-earthquake levels. Further discussion of the performance of Minase Dam is presented in Chapter 10, Performance of CFRDs. Cogoti Dam. Arrau, et al, 1985, reported on the performance of the Cogoti CFRD during the 1943, magnitude 7.9, earthquake. The dam, located approximately 90 km from the epicenter, settled nearly 400 mm but little other damage occurred. Increased leakage as a result of the earthquake or cracking of the concrete slab was not reported. The only repair to the dam subsequent to the earthquake was the replacement of rockfill at the crest where settlement of the rockfill away from the concrete face had occurred. The rockfill forming the body of the dam was dumped in lifts of “greatest height practicable”. At the time of construction, 1938, the rockfill for the embankment of the typical CFRD was end dumped in lifts from 3 to 5 m high. Crest settlement subsequent to completion of construction in the five years prior to the earthquake was about 400 mm, approximately equal to the instantaneous settlement that occurred during the earthquake. The crest settled an additional 300 mm in the 42 years between 1943 and 1985. In spite of the lack of compaction of the rockfill, the dam suffered remarkably little damage. Cogswell CFRD. Cooke (1995), reports on the performance of the Cogswell CFRD, constructed in 1933, during the 1991 Sierra Madre Earthquake, Magnitude 5.8. The crest of the dam settled about 40 mm and displaced horizontally about 20 mm. Vertical cracks occurred in the concrete face adjacent to each abutment. Cracks on the right side extended 11 m down from the crest; cracks on the left side extended 5 m down. During construction, the rockfill was dumped in 7 meter lifts without compaction and without sluicing with water. Upon completion of embankment construction, heavy rains caused the 80-m high fill to settle more than six meters. This unanticipated settlement was caused by the loss of strength of the fill upon saturation. Prior to the placement of the concrete face, the rockfill was thoroughly wetted to achieve further settlement. Further settlement of 400 mm occurred. In 1994, the dam was shaken again by the magnitude 6.7, Northridge Earthquake. An additional 20 mm of crest settlement was measured. Again, in spite of the lack of compaction of the rockfill, the dam suffered remarkably little damage. Sugesawa CFRD. Masumoto et al, 2001, reported on the performance of dams as a result of the October 2000 earthquake on the main island in Japan. The magnitude Mw was 6.6 with epicenter at a depth of 11 km. The Sugesawa dam consists of a concrete gravity dam, 73.5 m tall, and a CFRD saddle dam in the right abutment, 17 m tall. Peak ground acceleration in the right abutment was 0.36g. The performance of both dams was satisfactory. Torata CFRD. EERI 2003, reported on the performance of the Torata CFRD, during 2001, Magnitude MW 8.4 earthquake. The level of ground shaking at the site was estimated to range between 0.12 to 0.33g, and the mean PGA of 0.20g. The dam was built to divert the Torata River to the Cuajone pit project in Perú. The dam is a 130-meter-high CFRD. The upstream concrete face consists of 300 and 500 mm thick adjacent slabs, separated by vertical construction joints spaced every 15 m, fitted with water stops. Before the earthquake, maximum settlements at the



2-7

crest and mid-length of the concrete face slab were 460 and 190 mm, respectively. The maximum horizontal displacements at the same locations were 510 and 140 mm. Settlements and horizontal displacements of the concrete face at the crest as a result of the June 2001 earthquake, showed a maximum settlement and horizontal displacement of 62 and 36 mm, respectively. The earthquake caused minor cracking and joint separation in the concrete face near the left abutment. This was the result of seismic compression that occurred at that location. In summary, ECRDs and CFRDs have performed well during large earthquakes. In spite of the poorly compacted rockfill in the older concrete face rockfill dams, remarkably little damage has occurred. Anticipated Performance of a 200-m tall CFRD For purposes of the analysis presented herein, the following definitions are used: Maximum Credible Earthquake (MCE). The MCE is the largest reasonably conceivable earthquake that appears possible along a recognized fault or within a geographically defined tectonic province under the presently known or presumed tectonic framework. The MCE is defined as an upper bound of expected magnitude. Maximum Design Earthquake (MDE). The MDE will produce the maximum level of ground motion for which the dam should be designed or analyzed. Typically, for dams whose failure would present a hazard to life, the MDE is characterized by a level of motion equal to that expected at the site from occurrence of the controlling MCE. It is required that the impounding capacity of the dam be maintained when subjected to that seismic load. Operating Basis Earthquake (OBE). The OBE represents the level of ground motions at the dam site that would result in only minor and an acceptable level of damage. USCOLD defines the OBE as the level of ground motion with a 50% probability of not being exceeded in 100 years. The dams, appurtenant structures, and equipment should remain functional and damage easily repairable from occurrence of earthquake motion not exceeding the OBE. Where fault geometry and activity are well known, the deterministic method should be used to estimate the MCE. In locations where the nature of active faulting in not well known, an annual probability on the order of 1/3,000 to 1/10,000 is recommended to define input motion representing the MCE, depending on the risk rating of the structures (U.S. Committee on Large Dams, 1999). For projects classified with a high risk rating, the 10,000 year period of return is recommended for design. This corresponds to an approximate 1 percent probability of exceedance in a period of 100 years. Selection of Seismic Design Parameters. In this example, it is assumed that an active regional fault is located within about 26 km of the dam site and that the fault can generate an MCE equal to magnitude 7.8. An earthquake of this magnitude could produce peak ground acceleration at the dam site on the order of 0.6g. Because the dam is a high hazard structure, the MDE is selected equal to the MCE. The following parameters are selected:



2-8

Earthquake magnitude: 7.8 Peak bedrock acceleration at the dam site: 0.6 g. The anticipated response of the dam to the MDE can be evaluated using empirical methods of analysis based on actual performance of dams during earthquakes and on simplified analytical methods using procedures suggested Makdisi and Seed (1977) and Bureau (1997). Earthquake Severity Index. For this analysis, it is assumed that the rockfill materials for the dam will be obtained from required excavations and from quarries and that these sources, when properly compacted, will produce a well-graded high density rockfill. The anticipated response of the dam to earthquake motions can be estimated by direct comparison with the actual performance of rockfill dams to large earthquakes. This approach was followed by Bureau (1985) and is further expanded herein. Table 2-1 presents the deformation of rockfill dams in terms of the actual settlement at the crest of the dam and Bureau’s Earthquake Severity Index (ESI), as defined earlier. Figure 2-3 presents the relationship between Relative Settlement of the dam as measured at the crest and the ESI. The ESI for the MDE (PGA = 0.6 g, M = 7.8) is equal to 21.6. The estimated crest settlement taken directly from Figure 2-3 is as follows: Estimated crest settlement in response to the MDE, m Upper Bound of Data in Figure 2-3 1.4 Mean of Data in Figure 2-3 0.8 The anticipated response to a large earthquake compares favorably to the planned 15 m of freeboard above the normal maximum operating pool. During the 1990 earthquake in northern Luzon in the Philippines, the 120-m high Ambuklao Dam experienced crest settlement and deformation on the order of one meter (USCOLD, 1992). Makdisi and Seed Method. In the 1965 Rankine Lecture, Newmark introduced a method to estimate earthquake-induced displacements in embankment dams based on the concept that slope movements are initiated when inertia forces on a potentially sliding mass exceed the available yield resistance along the bounding surface of failure. Newmark treated the sliding mass as a rigid body. Makdisi and Seed (1977) modified Newmark's approach by recognizing that an embankment dam responds as a flexible structure and introduced a technique to estimate the amplification of the ground motions to the crest of the dam. The analysis, then, is based on estimating the maximum peak crest acceleration ümax for a given ground motion then determining the maximum acceleration of the potentially sliding mass, kmax. The yield acceleration, ky, of the sliding mass is estimated by finding the average horizontal acceleration coefficient in a conventional slope stability analysis which will obtain a factor of safety equal to 1.0. This coefficient is defined as the ratio of a horizontal destabilizing force (as might be caused by an earthquake) to the weight of the sliding mass. The ratio of ky to kmax can then be used to estimate



2-9

displacement at the crest of the dam. This estimated displacement has both a horizontal and vertical component. For this analysis, the amplification of peak ground acceleration from base to crest of dam was estimated by using Jansen's unpublished plot, titled "Measured Ratios (Amplification) of Crest and Base Accelerations at Embankment Dams in Response to Earthquakes", Figure 2-4. The value of kmax was assumed to be equal to ümax which is equal to the peak ground acceleration times the amplification factor. Based on previous analyses of high dams and judgment, the fundamental period of the dam was selected as 1.5 sec. The value of ky was determined based on conventional stability analysis as summarized below: Factor of Safety Yield without Earthquake Acceleration, ky Upstream slope 2.2 0.39 Downstream slope 2.1 0.35

6

5

4

3

2

1

Ampl

ifica

tion

Peak Ground Acceleration, g0 0.1 0.2 0.3 0.4 0.5 0.6

Notes: 1. The graph represents measured accelerations at embankment dams ranging widely in size,

geometry, materials, and foundation conditions. 2. The two plotted values for La Villita Dam for each indicated year are based on the positive

and negative amplitudes from asymmetric accelerograms of crest motion. 3. The envelope is drawn as an upper limit of amplifications, reflecting the average of La Villita

peak crest accelerations in the 1985 earthquake.

Figure 2-4 (unpublished Jansen, 1994)



2-10

The Makdisi and Seed charts, taken from Bureau (1997), are shown on Figure 2-5. The procedure indicates a displacement of about 1.3 m during the MDE. Use of a friction angle of 45 to 500 would yield factors of safety approaching 3.0. A larger yield acceleration and an estimated displacement less than one meter would result. Again, the estimated displacement compares favorably with the 15 m of freeboard. Bureau's Method. As an extension of the 1985 analysis, Bureau (1997) presented a chart, Figure 2-6, that relates the Relative Crest Settlement to the Earthquake Severity Index for several values of the friction angle of the fill material. The chart is based on finite element analyses of typical rockfill dams. Note that the settlement must be obtained by multiplying the height of the dam by the value read from the chart, then dividing by 100. Use of this method indicates a settlement of about two meters during the MDE, when using a friction angle of 400. Use of 500 friction would indicate a crest settlement on the order of 1 meter. Again, the estimated settlement compares favorably with the 15 m of freeboard above the normal maximum pool elevation.

0.0

-0.1

-0.2

-0.3

-0.4

-0.5

-0.6

-0.7

-0.8

-0.9

-1.0

Slid

ing

Mass

Dep

th R

atio

(-y/h

)

Maximum Acceleration Ratio (kmax/u max)2

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

M = 6.50M = 7.50M = 8.25

10.0000

1.0000

0.1000

0.0100

0.0010

0.0001

Norm

alize

d Di

splac

emen

t (u/

kmax

gTo)

Average Acceleration Ratio (ky/kmax) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

M = 6.50M = 7.50M = 8.25

Figure 2-5 Makdisi/Seed Procedure (from Bureau 1997) Anticipated Response. Based on the above empirical analyses, the estimated settlement or displacement at the crest of the 200-m tall CFRD is on the order of one meter. These movements that might occur during the MDE could lead to cracking and settlement of the fill at the crest and to cracking and joint separation within the parapet wall and the concrete face at the crest. An increase in leakage as a result of cracks and settlement could be expected but this would not result in a question concerning the fundamental safety of the dam.



2-11

100.00

10.00

1.00

0.10

0.01

0.001

Rel. C

rest

Set

tlem

ent (

Delta

H/H)

%

Earthquake Severity Index (ESI)

*Friction angle of the fill material

0.1 1.0 10.0 100.0

Figure 2-6 (from Bureau 1997) Dynamic analysis, based on the finite element method, using a equivalent linear model (for simplicity) or in high CFRDs using a non linear model, with the purpose of evaluation of the overall strain potentials and deformations of cross sections is becoming more and more common. In addition, hydrodynamic pressure effects on CFRD are receiving more attention. These effects deserve more attention for CFRDs with 1.3H:1V slopes and heights of 200m.

2.3 Defensive Design Concepts Materials, Concrete Face and Drainage The concrete face will be supported by processed crushed rock, high strength and high modulus materials. Because the water barrier is located at the upstream face of the dam, the embankment materials will not be saturated and, therefore, no deformations will take place during or subsequent to an earthquake as a result of increased pore water pressure within the CFRD. Rockfill zoning is such that permeability increases progressively from upstream to downstream. If the embankment consists of semi-pervious sands and gravels, an inclined drainage zone consisting of processed alluvium or crushed rock should be provided to separate the upstream zones from the downstream sand and gravel and rockfill zones. This drainage zone should be continuous from abutment to abutment and from the base to the crest of the dam. The drain should be connected to a high capacity underdrain located at the base of the dam. Provisions to monitor the flow from the underdrain should be incorporated into the design so that flow rates



2-12

can be monitored during first filling, during project operation and immediately after earthquakes and floods. Measurements of flow rates, deformations, and joint movements should be taken to evaluate the overall performance of the dam subsequent to earthquake. Design Features The design should incorporate defensive features against the effects of earthquake. Ample freeboard above the normal maximum pool elevation should be provided to mitigate against the effects of a major earthquake. The freeboard above the maximum operating pool elevation should be not less than three to four times the maximum estimated deformations that might occur during the maximum design earthquake. Often, the maximum operating pool elevation is located below the horizontal joint between the parapet wall and the concrete face. This design requirement automatically provides a freeboard, for high CFRDS, in excess of four or more meters.

2.4 Settlement and Compression Deformation Modulus The deformation modulus varies widely depending on the void ratio of the rockfill and the parent rock material. Uniformly graded rockfill, such as that used at Foz do Areia and Segredo in Brazil have low deformation moduli. Compacted gravel fill dams have considerably higher moduli. The moduli are derived from measurements of vertical settlement during construction and the calculated vertical fill load above the settlement gage, as follows: Ev = H * γr * h / 1000*s Where: Ev = Vertical deformation modulus, MPa H = Vertical depth of rockfill above the settlement gage, m γr = Unit weight of rockfill, kN/m3 h = Column of rockfill below the settlement gage, m s = Settlement of the gage, m Several projects that illustrate the range of calculated moduli, based on field measurements, are listed below:

Project Rock Type Deformation Modulus, MPa Foz do Areia Basalt 32

Segredo Basalt 45 Aguamilpa Gravel 190 Salvajina Clean Gravel 390

Alto Anchicaya Hornfels-diorite 145 Golillas Dirty gravels 210

Pinto and Marques (1998) evaluated the moduli of deformation of various rockfill materials with respect to the void ratio and the shape of the canyon or valley in which the several dams were



2-13

constructed. Their data are plotted on Figure 2-7 and are shown on Table 2-2. Two curves are plotted in the figure. The shape factor is defined as the area, A, of the concrete face in m2 divided by the maximum height of the dam, H, squared. For narrow canyons with shape factor, A/H2, equal to three or less, the indicated moduli of deformation are larger as shown by the upper curve in the figure. This appears to be the result of arching across the canyon and stress transfer of load into the abutments. Thus, the measured settlements are less than those that might be expected by evaluating the void ratio of the material and the calculated vertical load above the settlement gage.

400

350

300

250

200

150

100

50

0

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

E(M

P)

va

A - CethanaB - AnchacayaC - Foz do ArelaD SegredoE XingoF AguamilpaG SalvajinaH GolillasI ShiroroJ Lower PiemanK MackintoshL MurchesonM BastyanN Khao Laem0 Kotmale

- -

- -

- - - - - - -

2.3-G

ε

Figure 2-7 Correlation Deformation Modulus vs Void Ratio (Pinto and Marques, 1998) Estimating Construction Settlement Settlement during construction at any location within the embankment varies with the deformation modulus, the thickness of compressible material beneath the location of interest, and the load on the compressible material. The simple relationship, modulus of deformation, Ev, is equal to stress (the load placed on the compressible material) divided by strain (settlement of the top of the layer divided by the thickness of the layer) can be used to estimate the settlement, and, during construction, the relationship can be used to calculate the modulus of deformation based on measurements of settlement. If, for example, a column within an embankment dam is divided into 10 horizontal layers, the settlement at the top of the bottom layer, 0.1H in thickness, caused by the load of one layer, 0.1H in thickness, placed on top of the bottom layer is equal to: S = (γr * H2 ) / (100 * Ev)



2-14

Where: S = settlement in meters γr = unit weight of rockfill, MN/m3

H = height of the column within the dam in meters Ev = vertical deformation modulus, MPa For example, the settlement of the top of the 20-m thick base layer at the bottom of a 200-m tall CFRD with a deformation modulus equal to 100 MPa, under a load of one 20-m layer of rockfill with a unit weight of 22 kN/m3, is 0.09 m. Under the nine layers of rockfill, 180m, the top of the 20-m thick layer at the base of the dam would settle 0.09 times 9 equals 0.8 m. The maximum settlement within the dam would occur at about mid-height. At this location, five layers of compressible material are located below mid-height and five layers are located above. The settlement at mid-height in the example 200-m tall dam would be 0.09 times 5 times 5 equals 2.2 m. Note that the base of the basal layer does not settle because the analysis assumes an incompressible foundation. Also, at the instant of completion of the dam, no settlement of the crest occurs because the added load is zero. The above example demonstrates that the settlement of the surface of each layer will be proportional to the product of the number of layers below that elevation and the number of layers of fill above. When the embankment is divided into 10 layers as in the example, the settlement of each layer will be approximately proportional to the Distribution Factor shown in the following chart. It may be seen that the distribution of vertical settlement within the dam is roughly parabolic, with the maximum settlement occurring at about mid-height. On the day the dam is completed, the settlement of the crest and the base is zero.

Layer Number Layers Above the Top of the Layer Number

Distribution Factor

0 10 0 1 9 9 2 8 16 3 7 21 4 6 24 5 5 25 6 4 24 7 3 21 8 2 16 9 1 9 10 0 0

These simple techniques can be used to back-calculate the deformation modulus during construction when the dam is partially complete.



2-15

Construction and Behavior Parameters of some CFRDs

Joint movement, mm Dam Country Year and Height, m Rock Type

L m

A 103m2

γr kN/m3 ε Ev

MPa A/H2 D m O S T

Leakage l/s

ET** MPa ET//Eγ

Cethana Australia 1971 110 Quartzite 213 24 26.5 0.26 135 2.0 0.12 11.5 - 7.4 7 300 2.2 A. Anchicaya Colombia 1974 140 Hornfels-

Diorite 260 22 28.0 0.22 145 1.1 0.13 125 106 15 1800/180* 440 3.0

Fox do Areia Brazil 1980 160 Basalt 828 139 28.1 0.33 32 5.4 0.69 23 55 16 236/60 110 3.3 Segredo Brazil 1993 140 Basalt 705 86 29.1 0.38 45 4.4 0.34 - - - 400/50 170 3.8 Xingo Brazil 1994 140 Granite 850 135 27.4 0.27 37 6.9 0.30 30 34 - 180 190 5.1 Aguamilpa Mexico 1993 187 Gravel 660 137 26.2 0.19 190 3.9 <0.15 19 16 5.5 260/100 680 3.6 Salvajina Colombia 1984 148 Gravel 330 50 28.0 0.25 390 2.3 <0.10 7 22 14 60 630 1.6 Golillas Colombia 1984 130 Gravel 125 14 26.5 0.18 210 0.9 0.16 - 160 - 1080/650* 310 1.5 Shiroro Nigeria 1984 125 Granite 560 65 26.7 0.20 76 4.2 - 30 >50 21 1800/100* - - Lower Pieman Australia 1986 122 Dolerite - 35 28.0 0.24 160 2.4 0.22 7 70 - - 200 1.3 Mackintosh Australia 1981 75 Graywacke - 27 27.0 0.23 40 4.8 0.16 4.8 20 2.8 14 100 2.5 Murchison Australia 1982 89 Rhiolite - 16 27.0 0.17 225 2.0 0.04 12 9.6 7 2 590 2.6 Bastyan Australia 1983 75 Graywacke - 19 27.0 0.23 160 3.4 0.06 4.8 21.5 - 7 280 1.7 Khao Laem Thailand 1984 130 Limestone 1000 140 27.0 0.29 45 8.3 0.13 5 8 - 53 380 8.4 Kotmale Sri Lanka 1984 97 Charnokite 620 60 28.0 0.27 50 6.4 - 2 20 5 - - - *Initial leakage/value after repair works. **Computed by formula ET = 0.003 H2/D (MPa) Where: L = Crest length, m A = Face area in 1000s of square meters γr = In-situ unit weight of rockfill, kN/m3 ε = Void ratio Ev = Vertical deformation modulus, MPa D = Deformation of the face slab, measured at mid-height, with reservoir full, m O = Joint opening perpendicular to the perimeter joint, mm S = Settlement measured perpendicular to the face slab, mm T = Shear movement measured parallel to the plinth, mm ET = Deformation modulus, measured perpendicular to the face slab, as a result of reservoir filling, MPa

Table 2–2 From Pinto and Marques, 1998



2-16

Estimating Construction Compression During construction, settlement takes place causing the rockfill to compress. An estimate of the total compression to be expected can be estimated using the settlement expression derived above. Compression in terms of percent of the height, H, of a column within the dam is equal to the summation of the settlement within each of the 10 layers of the dam. The following expression is derived: C = S * 100/H * (9+8+7+6+5+4+3+2+1+0) = 45 * γr * H / E Thus, the compression, C, of a 200-m tall column within the example rockfill dam, with E equal to 100 MPa and γr equal to 0.022 MN/m3, is 2.0% of the column height. The compression, C, of a 100-m high column within the 200-m high rockfill dam would be about 1.0%. Using these simple procedures, the overall compression of the rockfill dam during construction can be estimated.

2.5 Estimating Face Slab Deformation Pinto and Marques, 1998, present an empirical approach to estimating maximum face slab deformation under the load of the reservoir. Maximum face deformation is measured normal to the face slab and occurs at about 0.4 to 0.5 of the dam height. Face movements, as with settlement during construction, are proportional to H2/Et. Et is the transverse modulus of deformation measured in the direction of movement under the load of the reservoir and is larger than the vertical modulus of deformation, Ev, measured during construction. The compression of the rockfill that occurred during construction creates a denser fill with a higher transverse modulus of deformation. The database developed by Pinto and Marques is presented in Table 2-2. As previously discussed, the valley shape factor, A/H2, affects the construction deformation modulus, Ev. In narrow valleys, with lower values of the shape factor, the arching effects across the valley reduce the load within a vertical column of rockfill at the maximum height section, thus reducing the measured settlement. The smaller settlement results in a larger estimate of the vertical modulus of deformation, Ev. In this case, the indicated transverse modulus would only be slightly larger than the calculated Ev. The ratio between the estimated Et, using the formula provided in Table 2-2, and Ev, is based on measurements of vertical settlement and maximum measured face displacement in the dam. The resulting calculated ratio was then plotted against the valley shape factor as shown in Figure 2-8. As can be seen from the figure, larger ratios of Et/Ev result from larger values of the shape factor, A/H2. The results of the data analysis by Pinto and Marques are shown in Figure 2-9. For example, the estimated maximum face deformation in a 200-m tall dam under full reservoir load would be on the order of 0.4 m, ifthe vertical modulus of deformation during construction, Ev, were equal to 100 MPa and if the dam were located in a valley with shape factor equal to 4.



2-17

These simple relationships between valley shape, modulus of deformation during construction, and the maximum height of the dam can be used to estimate the performance of the dam during the first filling of the reservoir.

9

8

7

6

5

4

3

2

1

0

1 2 3 4 5 6 7 8 9

A/H2

A - CethanaB - AnchacayaC - Foz do AreiaD SegredoE XingoF AguamilpaG SalvajinaH Golillas

- -

- -

I ShiroroJ Lower PiemanK MackintoshL MurchesonM BastyanN Khao Laem0 Kotmale

- - - - - - -

E/E T

V

E /E =T V

Figure 2-8 Ratio Transverse to Vertical Modulus as a Function of A/H2 (Pinto and Marques, 1998)

H /E (m /MPa)2 2V

1.4

1.2

1

0.8

0.6

0.4

0.2

0

100 200 300 400 500 600 700 800 900

D (m

)

A - CethanaB - AnchicayaC - Foz do AreiaD SegredoE XingoF AguamilpaG SalvajinaH Golillas

- -

- -

I ShiroroJ Lower PiemanK MackintoshL MurchesonM BastyanN Khao Laem0 Kotmale

- - - - - - -

Figure 2-9 Maximum Face Deflection versus H2/Ev (Pinto and Marques, 1998)



2-18

2.6 Estimating Seepage Through the Foundation and the Slab

Leakage is a key parameter that relates to the overall performance of the CFRD. Large leakage rates are an indication that damage has occurred to the perimeter joint and/or that the concrete face has cracked to some extent. Seepage through the foundation may also be a contributing factor to large leakage rates. Seepage through the foundation can be estimated following the usual concepts of flow in porous media, or more complex methods that include the effect of discontinuities in the rock mass, and the effect of the grout curtain. (Giesecke et al. 1992). The fundamental design concept of the CFRD is that the several embankment zones of the dam including the face support material, filters, transitions, underdrainage and the body of the dam must remain stable even if extremely large leakage rates were to occur. The ability of rockfill to accept and pass large flows is well known in the literature. Thus, if the embankment zones and the foundation treatment have been designed and constructed appropriately, the large leakage rates are not an indication that safety is a problem, but rather that remedial treatment may be required to reduce the leakage. Flow through Cracks The importance of designing and constructing appropriate treatment at joints is easily demonstrated by developing estimates of leakage through potential openings at the perimeter joint or through cracks in the face slab. The rate of flow through a crack is commonly expressed as being proportional to the crack width cubed. C. Louis, 1969, using the cubic equation and based on experimental studies, developed a model for flow through a crack as follows:

Where: q = unit flow rate, m3/s/meter of crack length g = acceleration of gravity = 9.81 m/s2

w = crack width, meters

i = hydraulic gradient, where i = h/d

h = frictional head loss associated with flow through the crack, meters d = depth of crack through which head loss occurs, meters v = kinematic viscosity of water, 1 X 10-6 m2/s at 20o C

m = roughness parameter, approximately equal to the dimension of protusions into the crack, meters

( )[ ]qgw i

v mw

=+

3

1 512 1 8 8 2.

.



2-19

If the roughness parameter, m, is defined as some fraction or multiple, a, of the crack width, w, then the above equation can be written:

For a crack with smooth side walls, such as a smooth joint surface in rock or a pre-formed joint in concrete, the value of “a” might be on the order of 0.1, (m = 0.1w). For a crack with rough side walls such as a hairline crack in concrete, the value of “a” might be on the order of 1.0 or 2.0 (m = 1.0 to 2.0w). The following table provides insight concerning the magnitude of the rate of flow that can be experienced through one-meter long cracks of several different widths with varying values of roughness. Note that the above equation cannot be used for turbulent flow conditions. Thus, the above equation is not applicable for flow rates that exceed about 0.2 l/s/meter of crack. A discussion of the use of the C. Louis equation as applied at several dams in Australia can be found in the paper by Casinader and Rome, 1988.

Estimates of Rates of Flow through a Crack

Crack width, mm

Roughness a

Head loss, h, m

Depth of crack, d, m

Gradient h/d

Flow rate, q, m3/s/m

Flow rate, q, l/s/m

0.1 0.1 100 0.6 166.7 1.24E-04 0.12 0.3 0.1 100 0.6 166.7 3.35E-03 3.35

0.1 1 100 0.6 166.7 3.31E-05 0.03 0.3 1 100 0.6 166.7 8.95E-04 0.90

0.1 2 100 0.6 166.7 1.39E-05 0.01 0.3 2 100 0.6 166.7 3.75E-04 0.38

For the examples presented in the table, a constant value of head loss through a constant depth of crack was used to illustrate the range of estimated flow rates that can occur through hairline cracks and through a damaged or poorly constructed joint. As can be seen from the table, hairline cracks, on the order of 0.1 mm wide, will not allow a large rate of flow, even under a high gradient and with rough side walls. Flow rates increase dramatically when the crack is 0.3 mm wide or wider and the wall of the crack is smooth. It is clear that great care is necessary in developing the joint details and in constructing the support of the face slab especially at the perimeter joint.

( )qw i

a=+

8175001 88 2

3

1 5.

.



2-20

2.7 References

Appendix M, Deformation Analysis, San Roque Multipurpose Project, Feasibility Study, March

1999. Arrau, L., Ibarra, I., and Noguera, G., “Performance of Cogoti Dam under Seismic Loading”,

Proceedings, Concrete Face Rockfill Dams, Design, Construction, and Performance, ASCE, October, 1985, p. 1.

Asteneh, A., et al., “Preliminary Report on the Seismological and Engineering Aspects of the

October 17, 1989 Santa Cruz (Loma Prieta) Earthquake”, Report No. UCB/EERC-89/14, Earthquake Engineering Research Center, University of California at Berkeley, October, 1989.

Barton, N., Kjaernsli, B., “Shear Strength of Rockfill”, Journal Geotechnical Engineering,

ASCE, Vol. 107 N. 7. Bureau, G., et al, “Seismic Analysis of Concrete Face Rockfill Dams”, Proceedings, Concrete

Face Rockfill Dams, Design, Construction, and Performance, ASCE, October, 1985, p. 479.

Bureau, G., et al, “Effects on Dams of the Loma Prieta Earthquake of October 17, 1989",

Newsletter, US Committee on Large Dams, Issue No. 90, November, 1989, p. 1. Bureau, G., Sinan, I., “Seismic Response of Los Angeles Dam, CA, during the 1994 Northridge

Earthquake”, 16th USCOLD Annual Lecture, Seismic Design and Performance of Dams, San Diego, CA, July, 1996, p. 281.

Bureau, Gilles, “Evaluation Methods and Acceptability of Seismic Deformations in Embankment

Dams”, Proceedings, 19th Congress on Large Dams, Florence, Italy, May, 1997. Casinader, R.J., Rome G., “Cracking of upstream concrete membranes on rockfill dams with

special reference to Winneke dam”, Proceedings, 15th Congress on Large Dams, Lausanne, 1985.

Casinader, R. J., Rome, G., “Estimation of Leakage Through Upstream Concrete Facings of

Rockfill Dams”, Proceedings, 16th ICOLD Congress on Large Dams, Q. 61, R. 17, San Francisco, 1988.

Casinader, R.J., Stapledon, D. H., “The Effect of Geology on the Treatment of the Dam-

Foundation Interface of Sugarloaf Dam”, Proceedings, 13th Congress on Large Dams, Q.48, R. 32, New Delhi, 1979.

Charles, J. A., Watts, K. S., “The Influence of Confining Pressure on the Shear Strength of

Compacted Rockfill Dams”, Geotechnique, Vol. 29, No. 4, 1980.



2-21

Cooke, J. B., “Cogswell Dam, History and Seismic Performance”, Unpublished Memo No. 131,

August, 1995. EERI, “Northridge Earthquake, January 17, 1994, Preliminary Reconnaissance Report”,

Earthquake Engineering Research Institute, March, 1994. EERI, “Southern Peru Earthquake of 23 June 2001, Reconnaissance Report”, Earthquake

Engineering Research Institute, Vol.19. January, 2003. pp 57-71. Giesecke J., Rommel M., Soyeaux R. 1991, “Seepage flow under dams with jointed rock

foundation”, Proceedings, 17th Congress on Large Dams, Vienna, 1991. Gosschalk, E.M., Kulasinghe, A.N.S., “Kotmale and Observations on CFRD”, Concrete Face

Rockfill Dams—Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Editors, ASCE, Detroit, October, 1985, pp 379-395.

ICOLD, “Selecting Seismic Parameters for Large Dams-Guidelines”, International Commission

on Large Dams, Bulletin 72, 1989. ICOLD, “Rockfill Dams with Concrete Facing-State of the Art”, International Commission on

Large Dams, Bulletin 70, 1989. ICOLD, “Rock Materials of Rockfill Dams”, International Commission on Large Dams, Bulletin

92, 1993. Jansen, R. B., “Estimation of Embankment Dam Settlement caused by Earthquake”, Water

Power & Dam Construction, December, 1990, p. 35. Leps, T. M., “Review of Shearing Strength of Rockfill”, Journal of the Soil Mechanics and

Foundations Division, ASCE, v. 96, SM4, p.1159-1170, 1970. Louis, C., “A Study of Groundwater Flow in Jointed Rock and its Influence on the Stability of

Rock Masses”, Rock Mechanics Progress Report No. 10, Imperial College, London, September, 1969.

Makdisi, F. I., Seed, H. B., “A Simplified Procedure for Estimating Earthquake-induced

Deformations in Dams and Embankments”, Report No. UCB/EERC-77/19, Earthquake Engineering Research Center, University of California at Berkeley, August, 1977.

Marsal, R. J., “Mechanical Properties of Rockfill, in Embankment Dam Engineering –

Casagrande Volume”, John Wiley, 1976. Matsumoto, N., Kadonatsu, T., Takasu, S., Yoshida, H., Taniguchi, M., “Performance of Dams

to the Tottori Earthquake of October 6, 2000”, Proceedings, Workshop, Modern



2-22

Techniques for Dams-Financing, Construction, Operation, Risk Assessment, ICOLD, German Committee on Large Dams, p. 341, September 2001.

Newmark, N. M., "Effects of Earthquakes on Dams and Embankments", Rankine Lecture,

Geotechnique 15, No. 2, pp. 139-160, 1965. Pinto, N. L., Marques, P. L., “Estimating the Maximum Face Deflection in CFRDs”,

Hydropower and Dams, Issue 6, 1998, p. 28. Seed, H. B., Makdisi, F. I., DeAlba, P., “The Performance of Earth Dams during Earthquakes”,

Water Power & Dam Construction, August, 1980, p. 17. Stewart, J. P., et al, “Northridge Earthquake--Geotechnical Structures”, Geotechnical News,

June, 1994. Swaisgood, J. R., "Estimating Deformation of Embankment Dams Caused by Earthquakes",

Presented at Association of Dam Safety Officials (ASDSO) Western Regional Conference, Red Lodge, Montana, May, 1995.

Tepel, R. E., et al, “Seismic Response of Eleven Embankment Dams, Santa Clara County,

California, as Measured by Crest Monument Surveys”, 16th USCOLD Annual Lecture, Seismic Design and Performance of Dams, Los Angeles, CA, July, 1996, p. 185.

USCOLD, “Guidelines for Selection of Seismic Parameters for Dam Projects”, US Committee on

Large Dams, May, 1996. USCOLD, “Observed Performance of Dams during Earthquakes”, US Committee on Large

Dams, July, 1992.



3-1

CHAPTER 3

FOUNDATION EXCAVATION AND TREATMENT

3.1 Foundation Treatment Objectives Foundation treatment for the CFRD consists of • Excavation,

• Foundation surface preparation at the plinth and beneath the body of the dam. This includes removal of unstable or unsuitable foundation material from beneath the plinth and the body of the dam. If this becomes impractical, defensive measures that preclude erosion and piping of the material must be utilized.

• Drilling and grouting and/or positive cutoffs beneath the plinth,

• Specific treatment of seams or defects both upstream and downstream of the plinth,

• Foundation and abutment drainage, and

• Combinations of the above techniques. The dam must accommodate variable foundation conditions and the selected foundation treatment must be compatible with the dam and with the foundation characteristics. Often, foundation conditions are erratic and difficult to define. Success depends on careful subsurface investigations to disclose strata or lenses critical to stability or seepage, design of appropriate foundation treatment, and careful execution of foundation excavation and treatment during construction. Construction often reveals conditions that were not observed during the site investigations. When this occurs, foundation treatment concepts must be reviewed and appropriate changes made. In summary, foundation treatment must achieve the following fundamental objectives: • Positive control of seepage beneath or around the plinth,

• Removal of unstable or unsuitable foundation material from beneath the plinth and the body of the dam,

• Preparation of foundation surfaces to receive concrete, filters and rockfill, and

• Limiting differential settlements of the plinth, the face slab and the perimeter joint.



3-2

3.2 Plinth Foundation Treatment

A continuous reinforced concrete plinth, cast on a competent foundation at an acceptable depth along the upstream toe of the dam, forms the ideal watertight connection between the concrete face slab and the rock foundation. The plinth is anchored into rock with steel bars and serves as the grout cap for foundation consolidation and curtain grouting. The plinth is normally founded on hard, non-erodible fresh rock that can be treated by grouting. This is necessary because hydraulic gradients on the order of 15 to 20 develop along the short seepage path under the plinth. With appropriate foundation treatment, however, weathered and jointed rock, fault zones, soil-filled joints and materials susceptible to possible erosion and piping, including firm saprolites, are acceptable. The plinth must be designed to accommodate the foundation conditions and hydraulic gradients within the foundation below the plinth will be reduced as necessary to fit the specific characteristics of the foundation. Criteria are presented in Chapter 4, Plinth, that relate plinth width to foundation conditions. When changes in foundation stiffness are abrupt, the possibility of significant differential movements must be carefully studied and the plinth design adapted to the findings. In general, for hard, competent, non-erodible rock surfaces, cleaning and preparation of these surfaces subsequent to general excavation for the plinth includes:

• Excavate soft material from cracks, crevices, joints, fractures, and cavities,

• Develop a comprehensive geologic map of the plinth foundation surface for the construction record,

• Clean surfaces with air and high pressure water, unless the rock surface can be damaged using water, in which case, use air only,

• Backfill cracks, crevices, joints, fractures, and cavities with concrete. This can be achieved concurrently with the placement of the foundation concrete below the plinth or with the placement of the plinth.

Plinths have been constructed on alluvial soils at several projects including two in Chile, Santa Juana and Puclaro. Castro, et al, lists 10 CFRDs with plinths founded on alluvium that are currently in operation, five of which are located in China. These dams vary in height from 28 m to Santa Juana, 106 m. Vertical cutoff walls were constructed within the alluvium and tied to the plinth to control seepage through the foundation. Where the CFRD is constructed on an alluvial foundation, it is important that the materials left in place will be stable under all static and dynamic (seismic) loading conditions and that deformations within the foundation are small such that the resultant movements at joints in the plinth or cracking of the concrete face will not lead to excessive leakage. Static and dynamic analyses of the proposed 131-m high Caracoles CFRD in Argentina indicate that the characteristics of the alluvium will allow the dam and plinth to be founded on the alluvium, Castro, et al. The alluvial gravels, cobbles and boulders that are typical of materials eroded from the southern part of the Andes Mountains in South America provide suitable



3-3

foundations. The materials are highly pervious, thus requiring cutoff, and, at the same time, exhibit low compressibility and are stable under large seismic loadings. Chapter 4, Plinth, presents further discussion concerning of the width of the plinth, internal and external extensions, and the analyses and means to ensure stability of the plinth and backfill concrete. The various defensive design measures that can be adopted to appropriately treat difficult foundations are illustrated with the following case histories. Salvajina Dam, Colombia, 1983 The plinth of the Salvajina dam was founded on a widely varying foundation. The lower 65 m of the dam abutments consist of hard quartz sandstone and siliceous siltstone with thinly interbedded hard shales. The upper 90 m of the plinth foundation consists mainly of a weathered to intensely fractured, interbedded siltstone and friable sandstone. In the upper part of the right abutment, a large igneous intrusion is present that is deeply weathered to a saprolite. This saprolite (residual soil: MH-ML according to the Unified Soil Classification System) is a reddish silty material sensitive to piping. Seams of hydrothermal alteration, prone to piping, of varying thickness (10-150 mm) are present in the siltstone. Plinth details adopted at this site are shown in Figures 3-1, 3-2, and 3-3 and can be summarized as follows: • The width of the plinth was increased from 1/20 to 1/25 of the water head H to 1/16 H. For

intensely fractured rock and intensely weathered rock, the width was increased to 1/9 H and 1/6 H, respectively to obtain hydraulic gradients of 9 and 6. Selection of construction details resulted in smaller actual gradients.

• In zones of altered sandstone and siltstone, a hand-excavated concrete back-filled cut off, 1 m

wide and 3 m deep, was tied to the plinth, see Figure 3-1, to prevent a seepage blow-out at the plinth contact. Where the saprolite was encountered, the trench depth was limited to 0.6 m and the cut off was made deformable by filling the trench with asphalt-impregnated sand (10-12% asphalt) to prevent cracking as a result of differential settlements, see Figures 3-2 and 3-3. A waterstop was placed at the junction of the cut off with the plinth.

• For the plinth resting on residual soil, differential settlements with respect to the adjacent

plinth founded on rock were expected. Cracking was avoided by constructing three transverse cold joints with PVC waterstops in the plinth to add flexibility, see Figure 3-2.

• The excavated residual soil and deeply weathered foundation surfaces downstream of the

face slab and upstream of the dam axis were covered with a concrete sand filter with an additional layer of the face supporting gravels as transition to prevent any possibility of migration of eroded fines into the embankment, see Figures 3-1 and 3-2. This treatment provides confidence that suitable filters placed downstream of the face slab can be used at almost all sites with rock foundations, even if they present extensive weathering zones.



3-4

• Deep, low pressure (100-200 kPa) consolidation grouting was carried out throughout the entire plinth foundation, except in the area where the low permeability saprolite was present. Consolidation grouting was carried out in a single stage through holes at 4 m spacing perpendicular to the slab and depths ranging between 5 and 10 m, depending on rock quality. Additional holes were drilled and grouted in different directions to intersect particular features, such as a steep set of open relief joints running parallel to the valley.

• Seams of weathered, crushed and friable rock were excavated to a depth of 3 to 4 times the

width of the seam and backfilled with either mortar or concrete. Particular attention was given to those features that cross the plinth foundation transversally.

• All upstream exposed rock slopes resulting from excavation for the plinth were covered with

a layer of steel-mesh-reinforced shotcrete to extend the seepage path. Sugarloaf (formerly Winneke Dam), Australia, 1979 At Sugarloaf (formerly Winneke) Dam, the depth of weathering of the siltstone foundation rock was such that the plinth could not be economically founded on groutable rock. As a result of the presence of dispersive clays in seams within both the highly weathered and fresh rock, specific measures were taken to minimize erosion of these seams under seepage forces. The presence of systematic weak seams in the foundation also gave rise to concern about the plinth sliding downstream due to water load. The following measures, as illustrated in Figure 3-4, were adopted: • To deal with the infill seams, present mainly in the upper 6 m of the highly weathered zone,

the upstream toe was excavated to at least 6 m into the highly weathered rock, in the form of a wide toe trench.

• The width of the plinth was set at 0.1 H or 6 m minimum. The rock foundation downstream

of the plinth was blanketed with a concrete slab 150 mm thick to such a distance that the hydraulic gradient across the plinth plus the downstream concrete extension was not greater than 2.

• Grout holes were flushed with air and water under pressure, prior to grouting, to flush out as

much of the dispersive clay as possible. • The foundation surface for a distance downstream of the concrete blanket, equal to half the

reservoir head, was covered with filter material. • To ensure the stability of the plinth against sliding, inclined anchors were placed to connect

the plinth to the rock at depth. Where anchors were not used, a buttress was constructed at the downstream side of the plinth extending it far enough into the embankment so that pressure from the fill could be more assuredly mobilized.



3-5

A B

C

D

EF

G

H

I

J

Q

K

R

L

S

M

TU

NO

P

3m 3m1.4m

0.6m

1.4m 3m

1m

8-13m 7-10m

2m

ABCDEFGHIJK

LMNOPQRSTU

Connecting slabInner slabDetail - see Fig 3-2Outer slabConcrete facePlinthPlanOuter slabPlinthShotcretePlinth

Connecting slabPermetric jointZone 1Face slabGrout curtainConcrete cut offAnchor barsZone 2Concrete sandSection A-A

Figure 3-1 Salvajina plinth founded on less competent rock



3-6

8m1

8m

8m

1.5

ABCDEFGHI

JKLMNOPQ

Perimetric jointFace slabConnecting slabVertical jointTransverse jointAsphaltic sand cut offSection B-B (see Fig 3-3)Transverse jointPlinth

Plan (see Fig 3-1 - Detail)PlinthRockAsphaltic sand cut offSteel reinforcementRockResidual soilSection A-A

A

B

A

A

B

J Q

B

K L

M

N

PC

D

E

F

G

H

I

O

N

Figure 3-2 Salvajina plinth founded on residual soil Section A-A



3-7

ABCDEF

GHIJK

Face slabConnecting slabPerimetric jointPlinthShotcreteConcrete sand

Zone 1Residual soilAsphaltic sand cut offGravel fill (Zone 2)Section B-B

A

B

C

H

I

JK

D

E

F

G

Figure 3-3 Salvajina plinth founded on residual soil. Section B-B



3-8

1

2

3

A

4

56

78

9

10

11

~0.5H

1.5 1.1 0.61 1 1

5.0m

~0.5

6.0m

~01H(6.0m)

2.56m

2.5m

3.0m

7.2m

B

C

D

E

I

FG

ABCDEFGH

Upstream toe detailConcrete faceAnchor bars at 1 m centers longitudinallyFoundation concrete 0.15 m thick, 32-25m wideAnchor bars at 2 m centers each way within thickened sectionOverlap 2 m minimumFine filter 42 m - 30 mHydraulic head at foundation level

I1234567891011

High plinth with buttressRockfillTransitionFiltersFoundation concreteConcrete facePlinthAnchor barsGrout curtainFoundationButtressOriginal ground surface

Figure 3-4 Winneke plinth details

Mohale Dam, Lesotho, 2001 At Mohale, two erodible seams cross the right abutment, one at about mid-height, the other toward the top of the abutment. It is conceivable that the seams could open as a result of reservoir loading. Treatment of the mid-height seam consists of multiple defenses: • an upstream impervious blanket placed in a trench excavated along the seam,



3-9

• over-excavation of the seam at the plinth and construction of a “socle” below the plinth, 50 m long and 18 m wide,

• “stitch” grouting across the seam from the upstream edge to the downstream edge of the socle in seven rows, 16 holes per row, and

• fine filter and transition protection over the seam beneath the entire body of the dam. In addition, an adit was driven from the downstream right abutment parallel to the mid-height seam to provide locations for observation and for access should remedial treatment become necessary. Puclaro Dam, 2000, and Santa Juana Dam, 1995, Chile The 80-m high Puclaro Dam in northern Chile is founded on alluvium, 113 m maximum depth. The design is based on several considerations: • Site investigations indicated that the alluvium is of low compressibility and stable under

seismic loadings, so that no substantial deformation will occur when the reservoir is filled,

• A diaphragm wall, penetrating the alluvium to a maximum depth of 60 m, will restrict seepage to a maximum of about 250 l/s, and

• A flexible structure can be designed and constructed to connect the diaphragm wall to the plinth so that any deformations experienced within the alluvium can be absorbed without distress. A detail of the conceptual design of this connection is shown on Figure 3-5.

The perimeter joint contains a bottom copper waterstop; a mastic filler with a Hypalon membrane covers the top of the joint. In addition, a non-cohesive soil covers the perimeter joint, the diaphragm wall and the concrete connector slabs. The 113-m high Santa Juana Dam is founded on alluvium up to 30 m deep. The design of the valley plinth is similar to the Puclaro design except that only one slab connects the diaphragm wall with the plinth instead of two as was selected for Puclaro. The reservoir was filled in 1997 and its performance to date has been excellent, with total seepage lower than 50 l/s. Both projects were constructed in areas of high seismicity. The maximum possible earthquake is estimated to have a return period on the order of 500 years and to produce a peak bedrock acceleration of 0.54g for Puclaro Dam and 0.56g for Santa Juana Dam.



3-10

The above case histories present a variety of design measures that are available to treat widely differing foundations to meet the fundamental objectives listed above. These measures: • Increase the seepage path length to reduce the hydraulic gradient and to eliminate the

possibility of erosion or piping in the foundation,

• Control, cut off and/or reduce the rate of seepage through the foundation, and

• Provide filtered exits for seepage beneath the body of the dam to prevent any conceivable migration of fines into the rockfill.

Pichi-Picun-Leufu, 1999, Argentina Pichi-Picun-Leufu dam is located in the region of Patagonia, in southern Argentina. This 40 m high dam has performed extremely well since completion, with measured leakage of about 13.5 l/s. Because of the highly dispersive local clays, the original design, compacted gravel with a clay core, was changed to compacted gravel with concrete face. The dam is founded on thick alluvial deposits, mainly consisting of sandy gravel with sporadic seams of sand and silt. In almost all of the plinth extensions, the gravel was removed 9 m. downstream of the plinth and substituted with well-compacted material. This allowed construction of the dam in advance of the plinth and foundation treatment and backfill over the exposed rock downstream of the plinth. Loose alluvial sands and silts were removed from below the body of the dam to avoid the potential for strength loss during or subsequent to an earthquake. The deposits, left in place, are dense and exhibit low compressibility. Measured deformations were small, because of the low compressible gravel in the dam and foundation. In general, excavation for the plinth was extended to a rock foundation using a concrete block of varying thickness. In the paleo-channel where the weathering of the rock was more intensive, an anchored concrete block 6 m. high was constructed under the plinth to be supported on sound rock.



3-11

El Pescador Consolidation grouting under low pressure was performed throughout the entire plinth foundation, considering the micro-fractured rock conditions. The typical 4-meter plinth extension, was increased to 8 m in the right abutment because of the presence of completely weathered and fractured rock. The dam has performed well, the reservoir is almost full and the leakage is below 3 l/s. Khao Laem, Thailand, 1985 This multipurpose project in central west Thailand faced extremely difficult foundation conditions at the alignment of the plinth and under the body of the dam (Watakeekul and Coles, 1985). The left abutment and valley section of the dam is founded on interbedded shale, sandstone, siltstone both calcareous and non-calcareous, locally interbedded with limestone. The strata have undergone severe faulting. Partially infilled cavities up to several meters across were encountered, many found along specific geologic features, such as faults. The right abutment is founded on a karstic limestone that extended hundreds of meters into the abutment. Extensive solution cavities and caverns were present up to several meters across that were partly or completely plugged with clay and sand infill. Other cavities were empty with the cavity walls coated with crystalline calcite. Solution features were found to depths of 200 m below the base of the dam. Along the plinth alignment, excavation to depths of 15 to 60 m was performed to a foundation surface from which cutoff treatment could be carried out. Foundation treatment included the following: • Open excavated and backfilled trenches on the left abutment, • Concrete diaphragm wall, total area, 15,500 m2, • Deep curtain grouting to a maximum depth of 180 m, and • High pressure air and water flushing to remove infill material before grouting. A permanent inspection gallery was added on top of the plinth for monitoring the effectiveness of the cut off and to provide access for remedial treatment. Right abutment treatment consisted of a combination of: • A mined concrete diaphragm wall providing positive cut off, • Grouting galleries, at a spacing of 14 m vertically, driven into the abutment 2.0 to 3.5 km, • A pile diaphragm wall in zones of major karst below the lowest gallery where open shafts

and trenches were not practical because of difficulty in dewatering, • Holes, 165 mm diameter, drilled into minor karst on 330 mm centers and backfilled with

tremie concrete, and • Deep curtain grouting, locally to a depth of 250 m below the lowest gallery. For the shell foundation, overburden excavation in the upstream one quarter of the base width was approximately to rock (Cooke, 2001). Under the remainder of the shell foundation, the



3-12

weathered decalcified sandstone and the limestone blocks floating in a clay matrix were left in place. In spite of the extensive foundation treatment, several leakage incidents occurred since reservoir filling in 1985. These incidents are described in Chapter 10, Performance of CFRDs.

3.3 Embankment Foundation Treatment The abutments downstream of the plinth and upstream of the dam axis should be stripped of all surface deposits to expose the high points of in situ rock. Any surface material remaining between rock points will not adversely affect embankment settlement after rockfill placement. An exception to this is the case of the hard firm, essentially incompressible till, found in Canada and other far north countries. In the riverbed, deposits may be allowed to remain except within a distance equal to 0.3-0.5 the head from the plinth. A more rigorous analysis is required, if the deposits are subject to loss of strength during the maximum design earthquake. In this case, an evaluation of the strength loss and an estimate of the subsequent decrease in the factor of safety will provide insight concerning the amount of alluvial deposits that will require removal. Erodible foundation material left in place may need to be protected with filter material in order to prevent the fines being washed into the rockfill, especially within 0.3-0.5 of the head from the plinth. The material left in place should not be so weak as to require local flattening of the embankment slopes to assure stability. For the material left in place upstream of the dam axis, which will be heavily loaded, it is required that its modulus be similar to the expected modulus of the rockfill, to avoid excessive face movements or uneven support. For a distance of 0.5 H with 10 m minimum downstream of the plinth, it is prudent to trim overhangs and vertical faces. The ANCOLD Guideline on CFRD, 1991, suggests trimming of overhangs higher than 2 m to a batter of about 0.5H:1V. In general, the requirements of embankment foundation treatment for the CFRD are less rigorous than for the ECRD.

3.4 Consolidation and Curtain Grouting Traditional Methods Grouting is carried out through the dowelled plinth acting as a grout cap, and outside the embankment body. Rigorous grouting standards must be met because of the very high hydraulic gradients (18 or more) that develop across the plinth. The design of the grout curtain is outside the scope of the Bulletin, but, in general, its extent should be decided only after consideration of the hydraulic head, the details of the site geology, the potential for leakage and piping and their consequence. Normally, three rows of short consolidation holes are used, and the central row is extended to form a grout curtain. For the CFRD the consolidation grouting is of special importance because of the relatively short seepage path through the rock directly under the plinth. The holes are oriented to intersect the major joint systems as revealed by the geologic mapping and, where necessary, additional holes are drilled



3-13

and grouted to intersect particular features observed as excavation for the plinth foundation progresses. For highly fractured rock foundations, it may be necessary to construct three rows of deep curtain grouting, plus the consolidation grouting. Final depth of the grout curtain is defined by the specific geological conditions encountered, but it is often specified to be within the range of 1/2 to 2/3 of the reservoir head at the location of the curtain. Grout pressure is normally 25 to 40 kPa per meter of depth, measured at the packer. These pressures are equal to 1.0 to 1.5 times the overburden pressure, calculated as the unit weight of rock times the vertical depth to packer setting. The maximum spacing of consolidation and grout holes is normally set at about 3 m. This allows detail exploration and treatment of the foundation and provides assurance that all open joints and cracks that require treatment are discovered and adequately treated. The split-spacing method is normally used to locate additional holes. The criteria to provide additional split-spaced holes varies according to the site conditions but for the CFRD is commonly a grout take larger than 50 kg of cement per linear meter (1/3 to 1/2 of a 94-pound sack of cement per linear foot) of grout hole. At some projects, a lower grout take, 35 kg/m, is used at the critical shallow depths below the plinth, and a higher grout take, 70 kg/m, at the deeper, less critical foundation depths. Stable mixes, that is, a water-cement mix with less than 5% sedimentation, are presently used. To achieve this requirement, mixes with a w:c ratio by volume larger than 2:1 (1.3:1 by weight) should not be used. Pre-hydrated bentonite rather than dry bentonite, in quantities between 1% to 2% of the cement weight, should be used to reduce sedimentation of the cement grains. Alternatively, super-plasticizers that limit sedimentation may be used. Some specifications have recently required on several dams that no embankment shall be in place within several meters of any grouting operation. This limitation is believed to be unnecessary by many designers since any grout leak into the embankment will do no harm. Unseen surface leaks may cause some waste of grout, but a satisfactory grout curtain is obtained inasmuch as the grouting criteria are not changed as a result of surface grout leaks. On the contrary, this limitation adversely affects the construction schedule and the final result is the placing of Zone 2 against a more segregated Zone 3 material, at the interface of the zones. GIN Method of Grouting Lombardi and Deere, 1993, introduced a grouting procedure defined by the “Grouting Intensity Number” (GIN). The main features of this method include: • A single, stable grout mix for the entire grouting process (water:cement ratio by weight of

0.67 to 0.8:1) with super-plasticizer to increase penetrability;

• A steady low-to-medium rate of grout pumping which, over time, leads to a gradually increasing pressure as the grout penetrates further into the rock fractures;

• The monitoring of pressure, flow rate, volume injected, and penetrability versus time in real time using computers and graphic presentations; and



3-14

• The termination of grouting when the grouting path on the displayed diagram of pressure versus total volume injected per meter of grouted interval intersects one of the following curves: Ø Limiting volume per meter of grouted interval,

Ø Limiting pressure, Ø Or limiting grouting intensity, as given by the selected GIN hyperbolic curve, a curve of

constant pressure times volume per meter. In practice, the grouting process using the GIN technique involves steady pumping of the grout at a low to medium rate, with a slow building up of pressure as the grout penetrates further into the rock mass. Grouting of any stage is stopped • When the volume injected attains a specified limiting value for a grouting interval,

• When the grouting pressure arrives at a previously selected limiting value, or

• When a given intensity of grouting has been attained as judged by the selected limiting value of the product of the pressure times the grout volume.

Specific limiting envelopes of pressure, volume and the product of pressure and volume are developed depending on the type of rock being grouted and on the depth at which grout is being injected. The criteria used at Mohale Dam, Lesotho, in competent basalt with tight contacts between flows are summarized in Table 3-1: Tests were performed to investigate whether an increase to 2.5 MPa pressure could be utilized below a depth of 20 meters. This pressure exceeds overburden pressure by a factor of about four times (overburden pressure at 20 m is about 0.6 MPa). The tests were conducted in eight curtain grout holes located in the valley floor in 5-meter stages from 20 m depth to 63 m depth. A total of 72 stages were tested with pressures at the packer up to 2.5 MPa. Plots of the individual GIN curves indicated the following: • Forty five stages, a substantial majority, showed no increase in grout take when pressures

were increased to 2.5 MPa. The data indicated that, in many instances, grout refusal in tight rock occurred at pressures ranging from 0.5 to 1.5 MPa.

• Hydraulic opening of joints, possibly on the contacts between flows, as observed by a sudden increase in grout take, occurred in four stages at pressures exceeding 2.0 MPa. Maximum reservoir pressure at a depth of 20 meters below the valley floor is about 1.6 MPa.

• Large grout takes at a pressure of 0.8 MPa were observed in two stages that crossed a shear zone. Features within the foundation such as shears that require attention were successfully treated at a pressure substantially less than 2.0 or 2.5 MPa. Subsequent re-drilling and grouting of these stages indicated low grout takes at 2.0 MPa pressure and no increase in grout take when the pressure was increased to 2.5 MPa.



3-15

Table 3-1

Base Grout Mix, Grouting Pressure, Gin Curve And Take Limitation

Depth (m)

Max. Pressure in bars (1.0 bar = 100 kPa)

Grout take Limit l/m*

Base Grout Mix by weight w:c *

Valley Floor

Abutment

Grout Intensity Number

Pressure in Bars times grout

volume in l/m*

0-5 1:1.5 5 5 500 200

5-10 1:1.5 10 7.5 1000 300

10-15 1:1.5 20 10 1500 300

15-20 1:1.5 20 20 1500 300

20-30 1:1.5 20 20 1500 300

30-40 1:1.5 20 20 1500 300

>40 1:1.5 20 20 1500 300 * w = water, c = cement plus fly ash. Take means liters of the base grout mix per meter of hole.

• Except for shears and lineaments, the basalt bedrock is extremely tight. Average grout take in the test stages (neglecting the two large takes in the shear zone) averaged 8 kg cement per meter at 2.0 MPa pressure, and 11 kg/m at 25 MPa. These low grout takes are indicative of the low permeability of the rock mass prior to grouting. In these conditions, the grout curtain is exploratory; features that require treatment are discovered by drilling and attempting to grout closely spaced holes.

The test results indicated that there was no benefit in increasing the maximum grout pressure below 20 m from 2.0 to 2.5 MPa. Pressures that greatly exceed the overburden stress can cause hydraulic jacking of pre-existing joints, which, in some instances, can result in foundation damage. High pressure is not required to discover and treat geologic features that require attention. It is noted that the foundations of many successful high head projects, world wide, have been grouted at pressures that approximate the overburden pressure or exceed the overburden pressure by a factor of no more than 1.5. Grouting the shear zone in the left abutment was completed at considerably lower pressure as summarized in Table 3-2:



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Table 3-2

Water Pressure And Grouting Pressure In Bladed Basalts And Lineaments

Depth (m)

Pressures (kPa)

Water Pressure Tests 1:1.5 mix or thicker *

0 - 5 200 250

5 - 10 325 375

10 - 15 450 500

15 - 20 575 625

20 - 30 700 750

> 30 1,200 1,250

* Thicker mix applies only for the lineament. A deep grout cut-off was constructed as part of the 140 m high CFRD in the high Andes of Peru, in sedimentary rocks at Antamina Project. GIN method was used and observations indicate that it has some limitations (Carter et al, 2003). In this project it became clear that GIN procedures were not achieving the desired grouting control in sedimentary rock with karst zones included. Four detrimental factors were identified;

• Hydrojacking resulting from excessively high injection pressures. • Dilation following hydrojacking shown by non-reducing curtain permeability and the lack of

curtain closure.

• High take grout stages terminated at the specified volume limit while still accepting grout at high flow rates, raising concerns that important features were not being treated.

• No relationship between the GIN criterion and the total volume injected, with GIN providing

no control for adequate treatment of the fracture system. Following detailed analysis of the ground response to grout, grouting procedures were revised to blend the best of the GIN approach with the key components of the Australian Method. (Ritchie et al, 2003).



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3.5 References

Anguita, P., Alvarez, L. and Vidal, L., “Two Chilean CFRDs Designed on Riverbed Alluviums”, Proceedings, International Symposium on High Earth-Rockfill Dams-Especially CFRD, Li Eding, (China) Chairman, Beijing, China, October 26-29, 1993, pp 83-95.

Casinader, R. J. and Stapledon, D. H., "The Effect of Geology on the Treatment of the Dam –

Foundation Interface of Sugarloaf Dam," Proceedings, 13th ICOLD Congress on Large Dams, Vol. 1, Q. 48-R. 32, 1979, pp. 591-619.

Casinader, R. J. and Watt, R. E., "Concrete Face Rockfill Dams of the Winneke Project,"

Concrete Face Rockfill Dams – Design, Construction, and Performance, J. B Cooke and J. L. Sherard, Editors, ASCE, Detroit, October, 1985, pp. 140-162.

Carter, T.G, Amaya F., Jefferies ,M.G., and Eldridge , T.L., “Curtain Grouting For the Antamina

Dam, Peru--Part 1-Design and Performance”, Grouting and Ground Treatment. Proceedings of the Third International Conference, ASCE, Vol. 2. No. 120.February, 2003, pp. 917-928.

Castro, J., Li Liu X., Macedo G., Caracoles dam – Analysis of the behavior of the combined

plinth – cutoff wall”, Proceedings, Second Symposium on Concrete Face Rockfill Dams, Brazilian Committee on Dams, Florianopolis, Brazil, October, 1999.

Cooke, J. B., "Progress in Rockfill Dams," The Eighteenth Terzaghi Lecture presented at the

American Society of Civil Engineers, 1982 Annual Convention, Journal of Geotechnical Engineering, ASCE, Vol. 110, No. 10, October, 1984, pp. 1381-1414.

Cooke, J. B., “Memo No. 178, Khao Laem Dam Performance, 1984-2000”, June 2001. Deere, D. U., "Cement Bentonite Grouting for Dams," Grouting in Geotechnical Engineering,

Wallace Hayward Baker, Editor, ASCE, New York, NY, 1982, pp. 279-300. Hacelas, J. E., Ramirez, C. A., and Regalado, G., "Construction and Performance of Salvajina

Dam," Concrete Face Rockfill Dams – Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Editors, ASCE, Detroit, October, 1985, pp. 286-315.

Hacelas, J. E., and Ramirez, C. A., "Salvajina: A Concrete-Faced Dam on a Difficult

Foundation," Water Power and Dam Construction, Vol. 38, No. 6, June, 1986, pp. 18-24. ICOLD, “Rockfill Dams with Concrete Facing-State of the Art”, International Commission on

Large Dams, Bulletin 70, 1989. Lombardi, G. and Deere, D. U., “Grouting Design and Control using the GIN Principle”, Water

Power and Dam Construction, Vol. 45, June, 1993, pp. 15-22.



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Marques Filho, P. L., Machado, B.P., Calcina, A. M., Materón, B., Pierini A., “Pichi-Picun-Leifu a CFRD of Compacted Gravel”, Proceedings, Second Symposium on Concrete Face Rockfill Dams, Brazilian Committee on Dams, Florianopolis, Brazil, October, 1999.

Noguera, G. and Vidal, L., “Design and Construction of Chile’s Puclaro Dam”, International

Water Power &Dam Construction, September, 1999, pp. 16-19. Ritchie, D.G, García. J.P, Amaya, F., and Jefferies, M.G., “Curtain Grouting For the Antamina

Dam, Peru--Part 2-Implementation and Field Modifications”, Grouting and Ground Treatment. Proceedings of the Third International Conference, ASCE, Vol. 2. No. 120. February, 2003, pp. 929-940.

Sherard, J. L., discussion of "Design Features of Salvajina Dam," by J. M. Sierra, J. E. Hacelas

and C. A. Ramirez, Concrete Face Rockfill Dam – Design, Construction and Performance, ASCE, October, 1985, Journal of Geotechnical Engineering, ASCE, Vol. 113, No. 10, October, 1987, pp. 1176-1179.

Sierra, J. M., Ramirez, C. A., and Hacelas, J. E., "Design Features of Salvajina Dam," Concrete

Face Rockfill Dams – Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Editors, ASCE, Detroit, October, 1985, pp. 266-285.

Watakeekul, S. and Coles, A. J., “Cutoff Treatment Method in Karstic Limestone-Khao Laem

Dam”, Proceedings, 15th ICOLD Congress on Large Dams, Q. 58, R. 2, Luasanne, 1985, pp. 17-38.



4-1

Chapter 4

PLINTH The plinth or toe slab connects the foundation with the face slab. The plinth design, dimensions, stability, construction and foundation treatment are most important. Dimensions of the plinth have been selected based on precedent and generally vary with reservoir head and with foundation conditions. Excavation below the plinth as might be caused by poor foundation conditions or the requirements for access to the dam during construction often result in substantial quantities of backfill concrete below the plinth. The resulting plinth and backfill concrete must be evaluated as an integrated structure for overturning and sliding stability.

4.1 Dimensions of the Plinth For competent, groutable, non-erodible rock, plinth widths have varied from 3 to 10 m or more, such that the hydraulic gradient through the foundation below the slab is on the order of 15 to 20. Occasionally, a hydraulic gradient through the foundation as high as 40 was adopted. The width is changed in several steps and is not tapered, mainly for construction convenience. For moderately to slightly weathered rock, the width of plinth has been increased, such that a maximum hydraulic gradient of 10 is achieved. The minimum width has been usually set at 3 m, although in Macagua dam (Prusza, et al) it was decided to limit the width of the plinth to 2 m only, because of the low height (22 m) and the massive and strong nature of the foundation granite. The minimum design thickness of the plinth is usually on the order of 0.3 to 0.4 m with thickness varying with reservoir head, H, in accordance with the following:

Slab Thickness, T, in m = 0.3 + 0.003 H

For construction convenience, a constant thickness is often specified. Dimensions for Poor Rock Conditions (see also Chapter 3, Foundation Treatment) The foundation rock conditions and specific erodible features within the foundation must be given special attention. Additional sealing upstream of the plinth and placement of a filter cover over the erodible feature downstream of the plinth are common treatment methods. Shotcrete or concrete with a filter cover has been used at several projects to treat specific features or to provide general treatment of an erodible foundation. Sealing a prominent potentially-erodible shear zone upstream and providing a filter cover downstream below the rockfill of the dam were adopted at Mohale Dam in Lesotho in addition to increasing the concrete treatment below the plinth. The concrete “socle” over the shear zone increased the effective width of the plinth to about 50 m, thus reducing the hydraulic gradient to about 1.5.



4-2

The 110-m high Reece Dam on the Pieman River in Tasmania is founded on a complexly folded and faulted Precambrian sequence of schist, phyllite and laminated quartzite (Li, 1991). These rocks are weathered to depths of 30 to 50 m. The left abutment presented pronounced relaxation with the foliation. Joint and fault planes were open up to 150 mm and infilled with potentially erodible silty clay and clayey silt. The solution adopted at Reece Dam included • Increasing the plinth width to reduce the hydraulic gradient to about 10 within the foundation

beneath the plinth, and

• Constructing a shotcrete blanket, 150 mm thick, reinforced with 8 mm wires on a 100 mm grid, for a distance downstream from the plinth equal to about one-half the reservoir head. A “Z” profile copper waterstop connects the shotcrete blanket with the plinth. This treatment forces a long seepage path through the foundation and increases the effective width of the plinth.

The criteria for maximum acceptable hydraulic gradient verses foundation conditions for Salvajina dam (ICOLD, Hacelas), where the foundation was quite variable, are summarized in Table 4-1. Also presented are the actual constructed widths of plinth and the as-constructed hydraulic gradients.

Table 4-1 Foundation Conditions and Width of Plinth-Salvajina Dam

Foundation Conditions

Maximum Acceptable

Hydraulic Gradient

As Constructed Hydraulic Gradient

Constructed Width of Plinth, meters

Hard groutable rock 18 -- 4 to 8

Competent rock 18 17.5 6 to 8

Intensely fractured rock 9 6.2 15 to 23

Intensely weathered rock-sedimentary 6 3.1 15 to 18

Intensely weathered rock-residual soil

from weathering of diorite

6 1.3 13 to 14

Plinth width criteria presented by Sierra, 1989, and repeated by Machado, et al, 1993 are presented in Table 4-2. Foundation conditions are divided into four categories from highly competent rock to completely decomposed residual soil. Plinth widths vary from 1/18 times the reservoir head over the plinth for the best foundation conditions to 1/3 for the worst foundation conditions.



4-3

Table 4-2 Foundation Criteria for Plinth Width Selection

A B C D E F G H I Non-erodible 1/18 >70 I to II 1 to 2 <1 1 II Slightly erodible 1/12 50-70 II to III 2 to 3 1 to 2 2 III Erodible 1/6 30-50 III to IV 3 to 5 2 to 4 3 IV Highly Erodible 1/3 0-30 IV to VI 5 to 6 >4 4

Where:

A = Foundation Type B = Foundation Class C = Minimum Ratio: Plinth Width/Depth of Water, full reservoir D = Rock Quality Designation, RQD, in % E = Weathering Degree: I equals sound rock; VI equals residual soil F = Consistency Degree: 1 equals very hard rock; 6 equals friable rock G = Weathered Macro Discontinuities per 10 m H = Excavation Classes: 1 = requires blasting 2 = requires heavy rippers; some blasting 3 = can be excavated with light rippers 4 = can be excavated with dozer blade

Alternative Concepts for Achieving Design Width If treatment of special foundation conditions is restricted to increasing the width of the plinth, substantial additional excavation will result. Simple geometric analysis will quickly demonstrate that doubling the plinth width will also greatly increase the height and volume of the excavation by a factor of two or more. Increasing the height of the cut may require flatter slopes to assure stability, which will further increase the height and volume of the excavation. A doweled plinth of constant width was used at Babagon Dam in Malaysia resulting in a hydraulic gradient of 15 to 20. The plinth width was effectively increased and the hydraulic gradient decreased to a desirable value by providing a 6 m wide downstream concrete slab. The thinly interbedded sediments (some friable) that crossed the plinth demanded conservative treatment and a longer seepage path. A doweled reinforced plinth, 4 or 5 m wide provides sufficient space to construct a three-row grout curtain. Downstream, the plinth can be extended beneath the body of the dam for a distance considered adequate to treat any special foundation condition. The downstream or interior plinth extension should be reinforced and connected to the upstream or exterior plinth with a waterstop. Placing a filter cover of material similar in gradation to the 2A zone (see Chapter 8) adjacent to the perimeter joint will preclude migration of silt-sized particles into the body of the dam, even if the downstream plinth were to crack.



4-4

This concept was first suggested by J. B. Cooke (Cooke, 1999) to reduce rock excavation for plinths along steep abutments in high dams. The concept can also be applied to advantage in flatter topographic conditions. The external plinth width is defined by the conditions for a practical grouting platform, while the internal slab width supplements the requirements for the allowable hydraulic gradient through the foundation. Specifications for groutable rock quality remain the same under the entire width of the plinth, both external and internal. The result is greater flexibility for excavation geometry and the potential reduction in the volume of excavation in steep valleys, as illustrated in Figure 4-1.

Potential economy in excavation

External plinth

Face slab

Internal plinth

0.5

1

31

H / 15

Figure 4-1, Typical Internal Plinth Cross Section (from Marulanda and Pinto, 2000)

In addition to Babagon, this concept has been applied with success in recent dams such as Corrales Dam in Chile (San Martin, 1999), Ita Dam in Brasil (Sobrinho, et al, 1999), and Pescador Dam in Colombia. Corrales Dam is partially founded on weathered granite, a low cohesion material that could allow particle migration if concentrated flow paths under the plinth were to occur. Within the left abutment, a 6 to 8 meter-wide plinth, 200 mm thick, was extended below the rockfill of the dam to prevent erosion and to reduce the volume of excavation. The external and internal plinth concept was also used at Ita, where the original plinth design width varied between 6.5 m and 4.0 m using the relationship H/20. Important savings resulted by the adoption of a standard plinth width as shown in Figure 4-2 that included a reduction of the excavation volume and up to 0,75 m3/m of concrete. A slightly different design was adopted for an internal/external plinth for a 17 m high shotcrete faced dam on the Sugarloaf Dam (formerly Winneke), Australia, where the internal and external sections of the plinth were monolithic, (Casinader and Watt, 1985).



4-5

0.30

3.00

0.60

2.50 1.50 Variable

Figure 4-2, Plinth Extension at Ita (from Marulanda and Pinto, 2000)

A method suggested by Materon, 2002, for evaluating plinth width selection has been applied at several CFRDs around the world. The method adopts the concept of external and internal plinths and applies the Rock Mass Rating (RMR) developed by Bieniawsky in selecting the combined width of the external and internal plinth. A summary of the method follows: • Select an external plinth width allowing sufficient width to execute the grouting, 4 to 5 m. • Classify the plinth foundation using the RMR system. • Determine the Plinth Design Index as follows (note that the index is equal to the hydraulic

gradient, H/L, where H is the reservoir head in m, and L is the dimension in m from the upstream edge of the external plinth to the downstream edge of the internal plinth at the contact of the plinth with the foundation).

Rock Mass Rating, RMR Plinth Design Index >80 20

60-80 16 40-60 12 20-40 6 <20 2*

For saprolite, and depending on foundation quality, using a diaphragm cutoff wall or excavating to a better foundation are alternatives. • Determine the maximum reservoir pressure, H, for the plinth sector and calculate the

required total plinth width by dividing H by the corresponding Plinth Design Index. • Calculate the internal plinth width as the difference between the total plinth width and the

external plinth width.



4-6

In addition to the above, areas that are susceptible to erosion should be treated with shotcrete and filters to a distance of approximately 40% of the hydrostatic head.

4.2 Geometry Downstream of the Plinth Foundation geometry downstream of the plinth influences the behavior of the perimeter joint. The depth of the fill at the perimeter joint should be 0.6 to 1.0 m as a convenient cushion for the slab; high fills adjacent to the joint are to be avoided. The change in depth of fill should be gradual with distance from the plinth. This is often achieved with the use of a sloped backfill concrete block placed below the plinth. Figure 4-3 illustrates the geometry of a concrete block at Mohale Dam where excavation resulted in a larger-than-normal concrete block to support the plinth. This geometry avoids the high fill adjacent to the perimeter joint and provides a gradual increase in fill thickness with distance from the joint. Similar geometry is also illustrated in Figure 3-4, Chapter 3, for the Sugarloaf Dam in Australia. The zone 2A filter material, placed immediately adjacent to the perimeter joint, should be well compacted to strict specifications to minimize settlement. In early projects, vibratory roller access adjacent to the perimeter joint was difficult. This often resulted in imperfect compaction at this location. The use of rectangular backhoe-mounted vibratory compactors is commonly specified to assure effective compaction adjacent to the plinth. In narrow valleys with steep abutments, it is difficult and expensive to provide favorable foundation geometry for the plinth. Excavation is minimized, and the plinth is doweled to the steep abutment walls. The depths of rockfill below the perimeter joint are large and substantial joint movements cannot be avoided. In narrow canyons, Golillas for example, the movements at the perimeter joint normal to the face (settlements) were much larger than those parallel to it (opening). Under these conditions, waterstops can be easily torn off. For high dams, excavation for the external plinth should extend more deeply into the abutment, similar to a road cut. Horizontal contours of the external plinth excavation should be perpendicular to the perimeter joint to provide reasonable access to construct a practical grout cap. Excavation for the internal slab should result in a gradual increase of fill height away from the perimeter joint as much as practical to minimize joint movements. Where necessary, a concrete block is constructed to create this geometry and to support the external plinth. Sliding and overturning stability of the plinth and concrete block must be satisfied as described below.

4.3 Geometric Layout of the Plinth The following description of the geometric layout of the plinth is taken from Marulanda and Pinto, 2000. The most common and practical design is to have the plinth laid out with horizontal contours normal to the plinth alignment. For horizontal plinths aligned parallel to the dam axis, such as those located at the maximum section on the valley floor, the basic geometry is clearly defined by the vertical cross section normal to the plinth alignment, Figure 4-4.



4-7

Note: Section taken perpendicular to toe slab control line

0m 1m 2m

A

B

E

C

D

ABCDE

Toe slabFace slabConcrete backfillSlope is 2H:1v perpendicular to dam axisAnchor bars, 4 m into rock

Figure 4-3, Concrete Backfill Analyzed for Stability, Mohale Dam, Lesotho

X

A

X1

Y

B

= arctg1/m

1

1

m

m

ho90º

Figure 4-4, Geometry, Horizontal Plinth

As the rockfill settlement under water load is essentially normal to the upstream face, plane AB is situated at a right angle to the face slope. For sloping plinths at the abutments of the dam, the



4-8

same condition holds. Graphical representation becomes more difficult as the plinth alignment changes both in plan and elevation. Figure 4-5, a plan view of the plinth alignment, presents the development of a practical relationship between the alignment angle "θ" and the plinth slope "n" (n horizontal:1 vertical). If El1 and El2 are the elevations of reference points Y1 and Y2, the following equations hold:

( )

21

21 11ant

−

−=

L

mEEθ

nm

=θsin

where "m" is the face slope, most commonly varying between 1.3 and 1.5, (1.3 to1.5 horizontal: 1 vertical). The cross section of a sloping plinth taken normal to the plinth alignment is shown in Figure 4-6. If the plinth is designed as a constant thickness slab, the majority of the cross section is essentially equal to that of the horizontal plinth. The plane AB remains normal to the dam face. The angle “α” varies in accordance with the alignment of the plinth. Designers have found various ways, often quite involved, to define the plinth geometry. A recent simplification of the procedures for plinth layout has been proposed by J. B. Cooke (Cooke, 1999) and is illustrated in Figure 4-4. Point "X1" is located on the foundation surface at the vertical projection of point "Y". The vertical distance, h0 = Y – X1, is established as a constant value, commonly about 0.8 m. This provides sufficient space for Zone 2A filter placement and compaction adjacent to the perimeter joint. For sloping plinths, the rockfill thickness normal to the foundation surface, “h”, is reduced. The height, h, for the inclined plinth can be calculated from the equation:

2θsinm1

+

= ohh

For h0 = 0.8 m and m = 1.3, the minimum value of h equals 0.63 m for θ = 90°, which is satisfactory for filter construction and performance.



4-9

Dam axis

Y1 EL 1

EL 2

n : 1

L1 - 2

m:1

= 0 orizontal plinth° for h

Figure 4-5, Plan View of Plinth Reference Line “Y” (from Marulanda and Pinto, 2000)

Y

B

1m

h90º

A

Figure 4-6, Geometry, Sloping Plinth (from Marulanda and Pinto, 2000)

The procedure for setting the plinth alignment remains unchanged. The reference plane for location of point "X", is now a plane parallel to the face reference plane and lower by the dimension "h0", say 0.8 m. The coordinates of points "X" and "Y" are the same; the plinth in plan is fully defined by the coordinates of the polygonal vertices. The main cross section of the plinth remains constant. Setting plinth face AB normal to the plane of the dam face is also required to establish plinth geometry. The angle "α" can be calculated from the equation:

1tan11

sintan2

22

22

2+

+

+=

θ

θα

mm

m



4-10

4.4 Stability of the Plinth In optimizing plinth alignment, excavation, and foundation treatment, a compromise is reached between rock excavation and concrete filling of depressions. Abrupt changes in abutment slopes or excavations for access and haul roads may result in construction of large concrete blocks to support the plinth. Access roads constructed across the plinth alignment and large concrete blocks should be avoided wherever possible. Appropriate scheduling and use of ramps within the body of the dam will minimize the need for access road construction across the plinth alignment. Because of environmental considerations, quarry sources are often required to be located within the reservoir. This requirement may result in the unavoidable use of access roads that cross the plinth. Stability of the large resulting concrete blocks must be checked against sliding and overturning. The stability of the block should be analyzed assuming the uplift pressure under the block is zero at the downstream toe and varies linearly to the full reservoir head at the upstream toe. No support should be assumed from the face slab on the understanding that the perimeter joint may have opened, and, although conservative, no resistance from the passive dowelled anchors is normally assumed in the analysis. The following text is quoted from ICOLD Bulletin 70, Rockfill Dams with Concrete Facing:

“It is necessary to ensure that the plinth is stable under the forces acting upon it. Dowels anchoring the plinth to the rock foundation are usually designed only to resist a nominal uplift pressure arising from foundation grouting. In the absence of any particular blanket downstream of the plinth to increase the seepage path, as previously described, the uplift pressure can be assumed to be zero at its downstream edge. Passive resistance from the rockfill or from the concrete face slab must be neglected because excessive movement of the plinth would be required to develop it and the face slab pulls away from the plinth when the water load is applied. In the absence of weak seams in the foundation, a sliding factor of 0.6 to 0.7 (Ø = 30°-35°) may be assumed. Under these conditions and a plinth of usual design thickness, it is not difficult to ensure the stability of the plinth. Excessive height of plinth due to overexcavation or other reasons causes the standard plinth to become unstable if the head exceeds about 30 m. Conventional overturning and sliding analysis must be conducted under this condition, taking also into consideration the least favorable geological discontinuities and the design criteria that the water pressure acting on the toe block is passed straight through to the rock foundation, without calling on the rockfill dam for any stabilizing force. If overbreak is minimal, say less than 0.50 m it is possible to ensure stability by installing sufficient grouted dowels properly oriented and prestressed rock anchors. If the plinth turns out to be excessively high across a sharp irregularity in the fresh rock surface, such as across a notched road cut excavation in a steep rock abutment or fault zone or other reasons, in addition to the grouted dowels and prestressed anchors, it may be required to provide a buttress at the downstream side of the plinth of such a length that pressure from the embankment fill can be relied upon. Under any abnormal



4-11

circumstances a conventional stability analysis is required and stabilizing measures adopted accordingly. Another critical problem arises in connection with higher than normal plinths. A high plinth is associated with a greater depth of compressible rockfill in the starter slab area which, in consequence, brings greater vertical offsets than normal along the most important perimeter joint upon reservoir filling. The high plinth is equivalent to a very steep abutment where the water load is transmitted through a higher column of rockfill. Golillas dam experience, Amaya and Marulanda, 1985, is rather significant in this respect. An analysis of the embankment deformations after first impoundment in Golillas has demonstrated that the magnitude of the fill settlements close to the abutments was similar to that in the center of the canyon and, therefore, movements along the perimeter joint in this very steep canyon tend to be mainly vertical.”

Plinth Stability, Mohale Dam, Lesotho The Mohale Dam in Lesotho is founded on a series of hard, competent basalt flows. The contacts between flows are tight; no weak horizontal seams exist. Several shears and zones of doleritic basalt cross the foundation and a construction access road crosses the plinth foundation on the left abutment. These features locally produced foundation irregularities that caused sloping rock surfaces on cross-sections taken perpendicular to the abutment contours, as illustrated in Figure 4-3. Where these conditions occurred, the plinths and underlying backfill concrete were analyzed for sliding and overturning using the following criteria: • Cohesion between concrete and rock was assumed to be 300 kPa.

• The friction angle between concrete and rock, φ, was assumed to be 450.

• Horizontal rockfill pressure on the sloping face of the concrete backfill was assumed to be equal to 0.25 times the reservoir pressure at the downstream side of the plinth. At Mohale, the rockfill pressure was included to increase stability.

• Vertical pressure on the plinth and on the sloping face of the concrete backfill was assumed to be equal to the reservoir pressure at the downstream side of the plinth.

• Vertical gravity force was assumed to be equal to the sum of the weight plinth, the concrete backfill, and the rockfill overlying the sloping portion of the concrete backfill.

• Uplift at the base of the block was assumed to be linear from the upstream heel to the downstream toe of the backfill concrete.

• For the two-dimensional analysis of sliding on the concrete/rock interface, a factor of safety of 1.5 on the frictional component and a factor of safety of 3 on the cohesion component was assumed. The ratio of resisting forces on the plane of sliding using the above factors of safety to the driving forces on the plane of sliding should be greater than or equal to 1.0.

( )N U cL

T

−+

≥

tan. .

φ15 3 10



4-12

where: N = Summation of total normal forces on the plane of sliding, U = Uplift on the plane of sliding, φ = Friction angle on the plane of sliding, c = Cohesion on the plane of sliding, L = Length of the plane of sliding, T = Summation of driving forces parallel to the plane of sliding.

• In addition, the sliding analysis was checked using the frictional component only. In this case, the ratio of the resisting forces to the driving forces should be greater than or equal to 1.0.

( )N UT

−≥

tan.

φ10

• Base pressures on the backfill concrete block were calculated and evaluated for the effects of overturning. The anchor bars were assumed to provide no resistance. If tensile stresses occur on the upstream edge of the plinth/concrete backfill, pre-stressed anchors should be considered.

The above criteria were applied to various cross-sections along the plinth alignment. In evaluating the results of the analyses, it was concluded that no pre-stressed anchors would be required at those locations that yield a tensile stress at the upstream heel of 100 kPa or less and where sliding criteria is satisfied. In addition, the percentage of sliding plane in tension did not exceed 10%. At Mohale, the criteria for the sliding analysis were found to be less critical than the criteria for overturning. Pre-stressed anchors were required over a length of about 35 m. The above criteria are considered to be quite conservative. In steep-sided canyons, it may be more reasonable to evaluate cross-sections taken perpendicular to the axis of the dam rather than perpendicular to the abutment contours and to give some credit to the passive anchor bars. For details of a similar analysis at Sugarloaf (formerly Winneke) Dam, see Figure 10 of Casinader and Stapledon, 1979. Shiroro Dam The 110-m tall Shiroro CFRD, constructed in the early 1980s, is founded on granite and diorite. Locally, deeply weathered zones, poorly sorted deposits of boulders and sand, and fault zones resulted in excavations to depths of a few meters to as much as 13 m below the plinth alignment. The resulting combined plinth and underlying concrete block was constructed with a vertical upstream face and a steeply inclined downstream face that, in cross-section at some locations, approximated a square. Use of the above criteria for overturning indicates large tensile stresses over most of the base. At some locations, the resultant of all forces falls close to the downstream edge of the toe block. The height and shape of the toe block was probably the major cause of the compression failures



4-13

in the face slab at locations above the perimeter joint. Other factors that are believed to have contributed to the face slab cracks include local stress concentrations caused by the interaction between the flexible fill and the rigid foundation, steepness of the abutment slopes, and interaction between adjacent face slabs.

4.5 Reinforcement, Waterstops, and Anchors Current practice is to provide one layer of reinforcement in the plinth equal to 0.3% each way. The reinforcement is located 150 mm clear distance from the top surface. The purpose of the reinforcing is to reduce cracks to inconsequential hairline widths. Local steel reinforcement is provided to prevent spalling at the perimeter waterstop prior to reservoir filling. Subsequent to reservoir filling, the perimeter joint opens and offsets and the spalling load disappears. Additionally, with no lower layer of reinforcement, the rock and the concrete are more compatible in the event of slight movement of the foundation upon reservoir filling. Current practice is to construct the plinth of any length as determined by topography and construction convenience. Reinforcement is continuous through the construction joints; waterstops are not provided at the construction joints. The anchor bars are arbitrarily designed; no specific analysis is performed to select anchor spacing and size. The anchors assure good contact with the foundation. Three rows of 26 mm diameter bars at 2 m centers are commonly specified.

4.6 References Amaya, F., and Marulanda, A., “Golillas Dam—Design, Construction, and Performance”,

Concrete Face Rockfill Dams—Design, Construction, and Performance”, J. B. Cooke and J. L. Sherard, Editors, ASCE, Detroit, October, 1985, pp 98-120.

Casinader, R. J. and Stapledon, D. H., "The Effect of Geology on the Treatment of the Dam –

Foundation Interface of Sugarloaf Dam," Proceedings, 13th ICOLD Congress on Large Dams, Vol. 1, Q. 48-R. 32, 1979, pp. 591-619.

Casinader, R. J. and Watt, R. E., "Concrete Face Rockfill Dams of the Winneke Project,"

Concrete Face Rockfill Dams – Design, Construction, and Performance, J. B Cooke and J. L. Sherard, Editors, ASCE, Detroit, October, 1985, pp. 140-162.

Cooke, J. B., “The Plinth of the CFRD Dam”, Proceedings, International Symposium on

Concrete Faced Rockfill Dams,ICOLD, 20th Congress, Beijing, China, September, 2000. Cooke, J. B., “Design of Width of Plinth for the CFRD”, Memo No. 142, January, 1997. Cooke, J. B., “CFRD Plinth Layout”, Memo No. 90, Revision, July, 1999. Cooke, J. B., “Shiroro Leakage and Repair”, Memo No. 81, with Addendum, October, 2000.



4-14

Hacelas, J. E., and Ramirez, C. A., "Salvajina: A Concrete-Faced Dam on a Difficult Foundation," Water Power and Dam Construction, Vol. 38, No. 6, June, 1986, pp. 18-24.

ICOLD, “Rockfill Dams with Concrete Facing-State of the Art”, International Commission on

Large Dams, Bulletin 70, 1989. Li, S. Y. et al, “A Concrete-Faced Rockfill Dam Constructed on a Deeply Weathered Foundation

(Reece, formerly Lower Pieman Dam)”, Proceedings, 17th ICOLD Congress, Vienna, Q.66, R.85, 1991.

Machado, B. P. et al, “Pichi Picun Leufu – The First Modern CFRD in Argentina”, Proceedings,

International Symposium on High Earth-Rockfill Dams, Chinese Society of Hydroelectric Engineering and ICOLD, Beijing, 1993.

Marulanda, A., Pinto, N. L. de S., “Recent Experience on Design, Construction, and

Performance of CFRD Dams”, J. Barry Cooke Volume, Concrete Face Rockfill Dams, ICOLD, 20th Congress, Beijing, China, September, 2000.

Materon, B., “Responding to the Demands of EPC Contracts”, Water Power and Dam

Construction, August, 2002. Prusza, Z., De Fries, K., Luque, F., “The Design of Macagua Concrete Face Rockfill Dam”,

Concrete Face Rockfill Dams-Design, Construction, Performance, Cooke and Sherard, editors, ASCE, Detroit, October, 1985.

San Martin, L., “Plinto en Granito Descompuesto y su Materializacion en el Embalse Corrales”,

II Symposium on CFRD dams, Bracold-Engevix-Copel, Florianopolis, Brazil, October, 1999. Sierra, J. M., “Concrete Face Dam Foundations”, De Mello Volume, Editor, Edgard Bluchter,

Sao Paulo, 1989. Sobrinho, J. A., Sardina, A. E., and Fernandez, A. M., “ Barragem de Ita – Projeto e

Construcao”, II Symposium on CFRD dams, Bracold-Engevix-Copel, Florianopolis, Brazil, October, 1999.



5-1

Chapter 5

PERIMETER JOINTS AND WATERSTOPS

5.1 Introduction

The perimeter joint connects the concrete face slab and the plinth of the CFRD to complete the upstream water barrier of the dam. The main function of the perimeter joint is to maintain a watertight seal against full reservoir load while allowing for anticipated movements between the plinth and face slabs. The plinth is anchored to rock and fixed in place or, in some instances, is founded on low-compressible alluvium. The face slab rests on the rockfill body of the dam, and will move and deform as the rockfill it rests on settles beneath it. Figure 5-1 illustrates how the face slab can move relative to the plinth in three different directions: normal to the perimeter joint (opening), normal to the face slab (settlement), and parallel to the perimeter joint (shear). Movement in any of these directions separates the face slab from the plinth.

Figure 5-1, CFRD Perimeter Joint Movements (from Pinto and Mori, 1988) Table 5-1 below summarizes measured perimeter joint movements for several modern CFRDs of compacted rockfill. Maximum total perimeter joint movements in the plane of the joint, calculated as the square root of the sum of the squares of the movements normal to the joint and normal to the face, are plotted versus dam height in Figure 5-2. As would be expected, there is a general trend of increasing joint movement with increasing dam height; however, there is a large amount of variability and scatter. The large variability in perimeter joint movements for higher CFRDs relates to variability in rockfill materials, placement, and treatment in the vicinity of the perimeter joint. This aspect is treated in greater detail in Chapter 8, Fill Materials. From examination of Figure 5-2, it can be concluded that for well-constructed CFRDs, total perimeter joint movement can be expected to be under about 30 millimeters for dams less than about 100



5-2

meters in height. For dams over 100 meters in height, total perimeter joint movements may be as high as 100 millimeters or greater.

Table 5-1 Perimeter Joint Movement

Perimeter Joint Movement, mm Dam Country Year

completed Height,

m Rock type O* S* T*

Data Source**

Aguamilpa Mexico 1993 187 Gravel 19 16 5 2

Tianshengqiao China 1999 178 Limestone and mudstone 16 23 7 6

Foz do Areia Brazil 1980 160 Basalt 23 55 25 1 Salvajina Colombia 1984 148 Gravel 9 19 15 1

Alto Anchicaya Colombia 1974 140 Hornfels-

Diorite 125 106 15 1

Xingo Brazil 1994 140 Granite 30 34 -- 2 Golillas Colombia 1984 130 Gravel 100 36 -- 1

Khao Laem Thailand 1984 130 Limestone 5 8 -- 1

Cirata Indonesia 1988 126 Breccia-Andesite 10 5 8 7

Shiroro Nigeria 1984 125 Granite 30 >50 21 1 Reece Australia 1986 122 Dolerite 7 70 -- 1

Cethana Australia 1971 110 Quartzite 11 -- 7 1 Kotmale Sri Lanka 1984 97 Charnokite 2 20 5 1 Xibeikou China 1991 95 Dolomite 14 25 5 4

Murchison Australia 1982 89 Rhyolite 12 10 7 1 Sugarloaf Australia 1982 85 Sandstone 9 19 24 1

Crotty Australia 1991 83 Gravel 2 27 -- 9 Mackintosh Australia 1981 75 Graywacke 5 20 3 1

Bastyan Australia 1983 75 Graywacke 5 21 -- 1 Chengbing China 1989 75 Lava tuff 13 28 20 5

Pichi-Picun-Leufu Argentina 1999 40 Gravel 2 12 1 3

Serpentine Australia 1972 39 Quartzite 1.8 5.3 -- 1,8

Paloona Australia 1971 38 Argillaceous Chert 0.5 5.5 -- 1,8

Tullabardine Australia 1982 26 Greywacke -- 0.7 0.3 1,8 * O = Opening, normal to joint, S = Settlement, normal to concrete face, T = Shear, parallel

to joint ** 1 ICOLD, Bulletin 70, 1989

2 Pinto and Marquez, 1998 3 Marques, Machado, et al, 1999 4 Peng, 2000 5 Wu, Hongyi, 2000 6 Wu, G.Y. et al, 2000 7 Kashiwayanagi et al, 2000 8 Fitzpatrick, et al, 1985 9 Knoop, B.P. 2002 (personal communication)



5-3

Due to the requirement to maintain a watertight seal while accommodating these movements, and the high pressure heads it can be subjected to under full reservoir load, the perimeter joint has received a great deal of attention by designers. This attention has focused primarily on design of the water-retaining barriers that form the perimeter joint. Design concepts used for CFRD perimeter joints are typically incorporated into the design of the vertical contraction joints of the CFRD face slabs as well.

180

160

140

120

100

80

60

40

20

00 20 40 60 80 100 120 140 160 180 200

Move

ment

(milli

met

ers)

Dam Height (meters)

Figure 5-2, Perimeter Joint Movements vs. Dam Height

(D) Dam height (meters) (M) Movement (millimeters) = (O2 + S2)0.5 see Table 5-1

5.2 Perimeter Joint Designs

The basic design concepts used for modern CFRD perimeter joints are relatively similar from one project to the next; however, the details that are developed based on these concepts can vary substantially. Evolution of the Perimeter Joint Pinto and Mori (1988) summarized the evolution of the perimeter joint in modern CFRDs of compacted rockfill, starting with the 110-meter high Cethana Dam in Australia. Cethana Dam, completed in 1971, was the first compacted CFRD over 100 meters in height. Two water barriers were used to provide a watertight but flexible connection between the plinth and face slab under full reservoir load. A W-shaped copper waterstop was used at the bottom of the joint between the concrete face slab and plinth. The shape of the waterstop was selected so that it could deform as the perimeter joint opens without tearing or rupturing. A rubber waterstop was placed at the middle of the joint. Measured leakage upon first filling of the reservoir was limited to about 50 liters per second (l/s), and reduced to about 10 l/s within five years.



5-4

Due to the small joint displacements and minor leakage measured at Cethana Dam upon its completion, only one rubber waterstop was placed in the middle of the perimeter joint of the 140-meter high Alto Anchicaya Dam in Columbia. Upon its completion in 1974 and subsequent filling of the reservoir, a leakage rate of 1,800 l/s was recorded. Some investigators thought that a lack of sufficient bonding between the concrete slabs and the rubber waterstop allowed water to pass around the waterstop and through the joint, and that this condition may have been a primary cause of the leakage. For others, the main reason for the leakage was the very steep abutment and the erosion that occurred during construction, as there was no protection for the support zone. Deep erosion occurred along the contact with the abutments. The backfill material was not properly compacted, had insufficient density and, therefore, was more deformable. To help reduce leakage around the joint, damaged concrete was replaced, and a reservoir of mastic joint sealing material was placed in the open joint. The mastic was covered by a wire mesh reinforced sand-asphalt mixture and clay, and held in place by steel plates. Leakage was dramatically reduced upon refilling of the reservoir, and the success of the repair was attributed to the performance of mastic joint sealing material, which would fill any opening that formed between the plinth and face slab. Perimeter joint designs for subsequent high CFRDs incorporated not only the two-barrier waterstop system successfully used for Cethana Dam, but also the mastic reservoir concept used to help successfully seal the perimeter joint of Alto Anchicaya Dam. The perimeter joint for the 160-meter high Foz do Areia Dam in Brazil was the first to use the three-barrier system. The successful performance of the perimeter joint of Foz do Areia has lead to the use of this same three-barrier concept on many high CFRDs. The perimeter joint of the 148-meter high Salvajina Dam in Columbia, completed in 1984, is shown in Figure 5-3. Perimeter Joint Design for Low CFRDs Although the three-barrier concept in use since Foz do Areia has been used for many CFRDs, regardless of height, CFRDs less than 100 meters in height and some that are more than 100 meters tall have successfully used only two barriers in the perimeter joint. The perimeter joints for the 80-meter high Mangrove Creek Dam in Australia and the 63-meter high Boondoma Dam in Australia both utilized bottom waterstops and middle rubber waterstops without the upper water barrier that is commonplace in high CFRDs (Mackenzie and McDonald, 1985 and Rogers, 1985). The perimeter joints for the 22-meter high Macagua Dam in Venezuela, and the 24-meter high CFRD for the Keenleyside Powerplant Project in British Columbia, Canada, both have a bottom waterstop and a reservoir of mastic at the joint surface (Prusza et al., 1985). The middle rubber waterstop was eliminated. The Pescador dam in Colombia (43 m tall) and the Antamina Dam in Peru (135 m tall), also eliminated the middle rubber waterstop. Both dams used a copper waterstop at the bottom and a reservoir of very erodable material on top of the joint. The dams have performed extremely well, leakage at Pescador Dam is less than 3 l/s, and leakage at Antamina Dam is about 1 l/s.



5-5

Perimeter Joint Design for Very High CFRDs Several CFRDs are currently planned that will exceed 200 meters in height, including the proposed 233-meter high Shuibuya Dam in China. These CFRDs can be classified as very high dams, and the high pressures and deformations that the perimeter joints of these dams will be exposed to require close attention. Several numerical studies and model tests have been conducted in China to test the effectiveness of various perimeter joint design concepts under high head conditions. These studies have been conducted primarily in support of design efforts for the 233-meter high Shuibuya Dam proposed for construction in China, and have concentrated on the effectiveness of cohesionless fines, mastic materials, and copper waterstops as water barriers for perimeter joints under high heads. Some of the more important preliminary conclusions reached by the various researchers involved in these studies include the following:

Hypalon bandMastic fillerCompressible wood fillerPVC waterstopCopper waterstopNeoprene cylinder

123456

Styrofoam fillerSand-asphalt mixtureFilter zoneSteel reinforcementAnti-spalling reinforcement

789

1011

1

1

2

33

4 6

68

9

1011

1110

7

510

Figure 5-3, Perimeter Joint for Salvajina Dam (from ICOLD, 1989)

1. Copper waterstops with a thickness on the order of 0.8 to 1.2 millimeters are reasonable for use on CFRDs between 100 and 234 meters in height; however, seepage is shown to occur around standard bottom copper waterstops under pressures of approximately 1.5 Mpa. When the base of the copper waterstop in contact with the plinth or face slab concrete is treated with mastic materials, the composite waterstop was shown to be watertight to a pressure of 2.5 Mpa with 10mm of deformation (Jia et al., 2000).



5-6

2. For upper water barriers consisting of mastic, the composition of the mastic material is important, particularly at very high heads. In China, mastics have been developed that maintain a watertight seal and are capable of large extensions (greater than about 600%) without breaking at both high and low temperatures under heads exceeding 200 meters (Jia et al., 2000 and Wangxijiong, 2000).

3. Model tests on prototype joints consisting of a copper bottom waterstop treated with mastic, and a membrane covered mastic reservoir, indicate little to no measurable leakage at pressures up to 2.5 Mpa and joint openings up to 100 millimeters (Tan, 2000).

4. Use of cohesionless fines in lieu of mastic as an upper water barrier is feasible as an alternative means for sealing perimeter joints of CFRDs greater than 200 meters in height (Ding et al., 2000).

5.3 Lower Water Barriers Nearly all of the CFRDs constructed after Alto Anchicaya Dam have utilized a bottom waterstop of copper, stainless steel, or sometimes PVC as the lower water barrier in the perimeter joint. The basic shape of the bottom waterstop is shown in Figure 5-4, and it is designed to safely accommodate any deformation that may take place between the plinth and the face slab without rupturing. The shape is generally referred to as a W-shape or F-shape depending on whether both vertical tabs are present.

Figure 5-4, Typical Bottom Waterstop Shape

Shapes and Sizes As shown in Figure 5-4, the basic shape of the bottom waterstop is designed with a high center section, or rib, to allow the waterstop to deform without tearing as movement of the perimeter joint occurs. The tabs on one or both sides of the waterstop are embedded into the concrete of the face slab and plinth, and serve to increase the seepage path around the waterstop. On some CFRDs the vertical tab is omitted or shortened in the plinth to permit better reinforcement placement, concrete placement and concrete consolidation.



5-7

Sizes of bottom waterstops vary somewhat from project to project, and the size of a waterstop selected for any one project should be based on anticipated joint movements and concrete and reinforcement placement requirements. The height of the center rib should be tall enough to allow the waterstop to deform without rupture. The height of the wings at either end of the waterstop should be as high as possible without interfering with reinforcement in the face slab or plinth. The base width of the bottom waterstop should be large enough to allow for proper placement and consolidation of concrete at the perimeter joint. Base widths for most bottom waterstops vary between about 250 and 500 millimeters. Metal Waterstops For CFRDs above 100 meters in height, either copper or stainless steel waterstops are used for the bottom water barrier at the perimeter joint. The selection of copper or stainless steel is typically based on factors such as ease of handling, water quality, and material costs. Copper is more easily formed and welded than stainless steel. Stainless steel has greater corrosion resistance and less likely to be damaged during construction than copper. Prices for stainless steel or copper will vary greatly depending on the project location and other economic factors. The metal sheets used to fabricate copper or stainless steel waterstops are typically on the order of 0.8 to 1.2 millimeters thick. Thinner sheets can be used on CFRDs of about 100 meters in height or less. Thicker sheets are recommended for higher CFRDs. Metal waterstops require special attention to prevent damage during construction. A pad of asphalt concrete or mortar is typically constructed under the waterstop to provide an even surface for placement of the waterstop, and to protect the waterstop from puncture or tearing due to sharp aggregates in the concrete face slab supporting zone. Use of asphalt concrete also provides a surface that has some ductility in order to protect the waterstop should joint movement occur. A strip of bituminous felt or PVC is also used to cushion the waterstop on the pad. The center rib is filled with neoprene or foam inserts to prevent the center section from being crushed under pressure from fluid concrete or external water pressure. A wood or steel box is placed over the portion of the waterstop protruding from the plinth prior to placement of the face slab concrete to protect it from damage during placement of adjacent rockfill materials. This point cannot be over-emphasized. All too often, damage to the copper waterstop has occurred because of poor construction practice. When damage occurs, a poor repair or no repair is often the result. Copper and stainless steel waterstops are typically formed in long, continuous pieces to minimize field splices. At the 145-meter high Mohale Dam in Lesotho, copper waterstops were formed as they were placed on site using a specially designed, continuous feeding and forming machine. Field splices are made by overlapping successive sections, and welding using a high fluidity electrode to ensure full penetration between the overlapping sections (ICOLD 1989). Spark testing is used to check field splices for quality. PVC Waterstops Bottom waterstops of PVC can offer several advantages over copper or stainless steel waterstops when they are used; however, their use has historically been limited to CFRDs lower than 100



5-8

meters in height. Figure 5-5 shows the PVC bottom waterstop used for one of the two CFRDs constructed for the 63-meter high Boondooma Dam in Australia. PVC bottom waterstops have also been used at the Macagua and Caruachi dams in Venezuela and the Keenleyside Powerplant Project in British Columbia.

Figure 5-5, PVC Bottom Waterstop for Boondoma Dam (from Rogers, 1985) PVC waterstops are substantially thicker than copper or stainless steel waterstops in order to resist pressures under full reservoir head PVC waterstop thickness can range from 5 millimeters for low CFRDs to over 12 millimeters for higher CFRDs. The greater thickness can simplify placement of the waterstop during construction, and reduces the risk of damage during construction as well. For the CFRD at the Keenleyside Powerplant Project, a 12-millimeter thick PVC waterstop was used for the bottom water barrier. The thick waterstop allowed for the elimination of both the support pad and the PVC or bituminous cushion strip normally required for thinner PVC waterstops or metal waterstops. The thick PVC section also eliminated the need for a protective cover during placement of the adjacent rockfill. The protruding portion of the waterstop was temporarily bent upwards against the plinth to allow for placement and compaction of the face supporting zone beneath the waterstop at the perimeter joint. As shown in Figure 5-5, a thin tab is left in place along the bottom of the center section of the waterstop to help keep the center rib open and clear prior to joint movement. This eliminates the inserts that are required for metal waterstops. Sections of PVC waterstops are typically spliced in the field by butt-welding adjacent sections together. No additional welding materials are required for splicing of PVC waterstops. Bottom Waterstop during Construction Many projects have used wood planking and steel frames to protect the perimeter joint and the protruding waterstops prior to construction of the face slab. (Fig 5-6)



5-9

Figure 5-6, Wood Planking Protecting the Cooper Waterstop

5.4 Middle Water Barriers Middle water barriers for perimeter joints consist of flat or dumbbell shaped PVC or Hypalon waterstops such as those used for construction and contraction joints in concrete hydraulic structures. Each end of the waterstop is embedded into the plinth and face slab concrete. Various shapes used as middle waterstops in CFRDs are shown in Figure 5-7. Flat waterstops typically have rows of ribs along each side to provide for better mechanical interlocking with the face slab or plinth concrete. Dumbbell-shaped waterstops have solid core bulbs on either end for the same purpose. Center bulb waterstops include a hollow bulb at the middle of the waterstop. They are considered preferable to other middle waterstop shapes due to their ability to undergo greater deformation before tearing or rupturing. Additional measures are sometimes taken to protect middle waterstops from being cut by sharp concrete edges as the face slab offsets from the plinth. At 148-meter high Salvajina Dam in Columbia, neoprene cylinders were placed at alternate corners to protect the middle waterstop (ICOLD, 1989).



5-10

A B

C D

Center bulb waterstop with barbellsCenter bulb waterstop with ribsFlat waterstop with barbellsFlat waterstop with ribs

ABCD

Figure 5-7, Typical Middle Waterstop Shapes (from USACE, 1995)

Although middle waterstops of several different shapes have been used successfully on high CFRDs in the past, the value of these waterstops has been questioned. As discussed earlier in this chapter, one of the reasons given for the leakage recorded during the initial filling of Alto Anchicaya was poor performance of the middle PVC waterstop. Cooke and Sherard (1987) question whether middle bulb waterstops may rupture under the high pressures and large joint movements experienced at the perimeter joints of high CFRDs, and also question whether the location of the middle waterstop can impair proper placement and consolidation of concrete at the perimeter joint. Tests conducted to determine the performance of middle PVC waterstops under large joint displacements, reported by Pinto and Mori (1988), indicated that these waterstops tended to rupture after about 25 millimeters of displacement. However, tests on center bulb waterstops reported by Guiduci et al. (2000) showed that they could undergo up to 115 millimeters of displacement without rupturing. Thus, if middle waterstops are used as a water barrier, center bulb waterstop shapes are recommended.

5.5 Upper Water Barriers For CFRDs over 100 meters in height, the upper water barrier typically receives the most attention by designers. This water barrier is installed after the plinth and lower part of the face slab are constructed, and it provides the greatest opportunity to achieve a reliable and robust water barrier for the perimeter joint. As discussed previously , the first use of an upper water barrier was for the repair of the perimeter joint at Alto Anchicaya Dam. The successful application of mastic joint sealing materials at Alto Anchicaya resulted in the adoption of a reservoir of mastic as the upper water barrier for many future high CFRDs. Other upper water barrier concepts have been developed and successfully incorporated into high CFRDs as well; however, the general concept of providing a reservoir of joint sealing material to fill the gap left as the face slab separates from the plinth remains the same.



5-11

Mastic Joint Sealants The application of mastic as a joint sealant for the upper water barrier of the perimeter joint is common and widespread. The most common detail consists of forming a reservoir of mastic at the top of the perimeter joint by chamfering the top edges of the plinth and face slab. Mastic is then placed into the joint until it forms a mound above the surface of the joint. A flexible and durable covering, anchored at each side to the plinth and the face slab, is placed over the mounded mastic to protect it and so that the water pressure from the dam reservoir can be applied evenly over the surface of the material. As movement of the perimeter joint occurs, the mastic is forced into the joint under the pressure of the reservoir to fill the gap that forms, thus maintaining a seal against leakage through the joint. Figure 5-3 shows the mastic reservoir detail used at Salvajina Dam in Colombia. Results of tests conducted on the effectiveness of mastic as an upper water barrier indicate that appropriate attention must be paid to the mastic joint detail, beginning with the proper selection of the mastic materials to be used. Mastic is a compound material containing several components that affect its workability and performance as a joint sealing material. The main component of mastic is a bitumen base that increases in fluidity as it is heated, and hardens when cooled. Additives and fillers are used to increase the fluidity of hot mastic, as well as to increase or decrease the deformability of the mastic after it has cooled. Thus, in high temperature environments, a particular type of mastic may be highly deformable and may even flow under its own weight if not carefully placed and secured in the perimeter joint. In some instances mastic placed over perimeter joints has been reinforced with wire mesh to prevent it from flowing down sloping plinths near the abutments or face slab contraction joints. In environments where the temperature may fluctuate widely, and in colder regions, care must be taken to select a mastic composition that maintains its deformable characteristics at temperatures far below freezing. For acceptable performance, mastic materials should be viscous enough to flow into the perimeter joint when movement occurs, but be sufficiently strong and elastic so that it does not break down or separate under high pressures. Mastic can become brittle, crack and separate from the concrete in the perimeter joint, eliminating its effectiveness as a joint sealing material. Golillas, in Colombia, is an example of mastic materials that became brittle and cracked. The reservoir was not filled for about four years after construction because the tunnel to convey water to the city of Bogotá was not finished. Because of exposure to weather over several years and being at an altitude of about 3000 m, most of the mastic material became brittle and did not provide a defense during the initial filling. The poor performance of mastic materials in laboratory tests reported by Pinto and Mori (1988) may have been the result of poor mastic properties above any other factors. Mastics that provide several hundred percent extension under a wide range of temperatures are recommended. Mastic is placed in the perimeter joint using several different techniques. A common method is to heat mastic in batches to a temperature such that it can be easily formed and spread in layers in the prepared concrete joint. The temperature of the mastic must be high enough so that each successive layer is properly bonded to the previously applied layer when applied in this fashion. Otherwise weak planes or laminations may form in the mastic, eliminating its effectiveness. Pre-formed lengths of mastic, or logs, can also be used, either supplied in a usable form directly from



5-12

the mastic supplier or made onsite. Pre-formed logs have some advantages over hot-applied mastic, including ease of placement in the perimeter joint and greater material quality control. Lengths of mastic are placed directly into the prepared joint. Mastic materials mixed in a factory-controlled environment, or at a suitable onsite facility, will be more uniform in composition and of a higher quality than mastics mixed in the field just prior to application. Preformed mastic logs (typically 1 to 1.5 meters long when ordered from the supplier) are joined by heating each end, and then pressing each end together. Preformed mastic logs were used in the perimeter joints of the recently completed CFRD of the Keenleyside Powerplant Project. Careful cleaning and treatment of the concrete surfaces on which the mastic will be placed is important. Common practice is to carefully wash and clean the surface of the concrete, and pre-treat the surface with a coating of heated mastic prior to placement. Companies that supply mastic for such purposes provide instructions for proper pre-treatment of concrete surfaces. Some designers specify that a small diameter (15 to 16 millimeters) neoprene tube be placed in the groove of the joint before the mastic sealant is applied. The tube serves to prevent the mastic from flowing into the joint until a sufficiently wide gap has formed. Such a detail is not considered necessary; however, as long as enough mastic is provided to completely fill the joint as it opens. Mastic joint sealants must be properly covered and protected in order to provide a long lasting upper water barrier. Although coverings consisting of PVC membranes, and even conveyor belting material (Morris, 1985), have been successfully used in the past, Hypalon has been the preferred covering material because of its resistance to weathering and ozone attack. Only materials that offer exceptional resistance to ozone deterioration, weathering and stresses from reservoir pressure should be considered if an alternative to Hypalon is desired. The covering should be wide enough to cover the mastic material, and should form a convex upward shape, along with the mastic, when secured in place. The covering will never be in tension when the joint opens and the mastic is forced into the joint. The covering is secured to the concrete of the face slab and plinth either by galvanized rigid steel angles or galvanized flat bars anchored into the concrete at regular intervals. Flat bars are more convenient to use on rough concrete surfaces, but must be anchored at closer intervals (Cooke and Sherard, 1987). Flat bars anchored using concrete expansion anchors at 400 millimeter centers were used for the CFRD of the Keenleyside Powerplant Project. Joint Sealing With Cohesionless Fines In their 1988 paper, Pinto and Mori proposed an alternative to the mastic joint sealant system. This alternative considers replacing the reservoir of mastic covering the perimeter joint with a zone of fine sand and silt. Figure 5-8 shows their proposed alternative. The key to this alternative is the addition of a fine filter zone to the rockfill placed behind the perimeter joint. As movement of the perimeter joint occurs, the fine sand and silt is washed into the gap that forms but retained by the fine filter zone behind the slab. The fines clogged joint limits leakage through the perimeter joint.



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18

4 7 62

9

5

3

Fine sandFilter materialFilter material with 5% cementToe slabFace slab

12345

Sand-asphalt padCopper bottom waterstop Silty fillNormal transition material

6789

Figure 5-8, Upper Water Barrier Using Cohesionless Fines (from Pinto and Mori, 1988) The 187-meter high Aguamilpa Dam in Mexico incorporated the cohesionless fines concept as a joint sealing material, utilizing fly ash for cohesionless fines (Gomez, 1999). A reservoir of fly ash was placed on the surface of the perimeter joint, protected by a galvanized steel cover. The upper water barriers for the 178-meter high Tianshengqiao No. 1 Dam and the 124-meter high Heiquan Dam in China also use a zone of fly ash for the cohesionless fines (Jiang and Zhao, 2000). A similar concept was adopted for the 145-meter high Mohale Dam in Lesotho (Gratwick et al., 2000). The Antamina Dam in Peru and the Pescador Dam in Colombia have used this concept not only for the perimeter joint but also for all expansion joints. The cohesionless fines are placed inside a hypalon cover (membrane) that is securely attached to the concrete. At both dams, the membrane was placed on top of a geotextile and secured with a steel angle anchored to the concrete. This tight connection precluded the possibility of washing the cohesionless fines during the operation of the reservoir. The key to the success of upper water barriers using cohesionless fines is the proper design and placement of the fine filter zone behind the perimeter joint, and the proper selection of the cohesionless fines material to be used. The gradation of the fine filter zone placed behind the perimeter joint must be such that the cohesionless fines are not washed through the perimeter joint and into the rockfill body of the dam. Additional details for the design and placement of this zone are provided in Chapter 8, Fill Materials. The cohesionless fines used for this upper water barrier concept must contain enough fine particles (silt sizes or finer) to provide a low permeability barrier to flow from the reservoir, but must not have any cohesive properties that could prohibit the erosion of this material into the perimeter joint. Due to its fineness and non-cohesive properties, fly ash is a preferred material for this purpose. However, fine silty sand with non-plastic fines or any other fine, non-cohesive material should be able to perform this function as well. Regardless of the type of cohesionless fines used, this zone must be adequately protected from the reservoir. An upstream, zoned earthfill buttress, a common feature on many of the higher



5-14

CFRDs, serves this purpose up to the top of the buttress. Above the earthfill buttress zone, a membrane cover should be used to protect the cohesionless fine, similar to those used for mastic materials. Additional details of this upper earthfill buttress zone are also provided in Chapter 8, Fill Materials. Casinader (private correspondence, 2004), reports that at Sugarloaf and Kotmale dams, a relatively small plinth backfill of a few meters of confining fine material was taken up the whole length of the plinth. This was used instead of a larger earthfill buttress at the toe of the dam within the valley section of the dam. Where abutments are steep, this technique is not practical. Other Upper Water Barriers Although upper water barriers utilizing mastic and cohesionless fines are the most common methods used on CFRDs of all heights, other concepts for upper water barriers have been developed recently. A waterstop-type barrier was developed for the recently completed 125-meter high Ita Dam in Brazil, consisting of a triangular shaped neoprene or EPDM waterstop that can be wedged into the joint between the plinth and the face slab, or the vertical contraction joint between adjacent face slabs. The waterstop is designed so that it can expand as the joint opens. The force of the reservoir water pressure keeps the waterstop seated in the joint. According to test results reported by Mori and Sobrinho (1999), the new waterstop was successfully tested to static heads of up to 260 meters and about 60 millimeters of joint movement. It is noted; however, that the waterstop was used for the upper water barrier at vertical contraction joints only. A mastic reservoir was used for the upper water barrier in the perimeter joint. A similar concept was used for the 125-meter high Machadinho Dam in Brazil (Mauro et al., 1999). In an attempt to include a rubber waterstop at the perimeter joint, without the complications caused by middle rubber waterstops, designers of the 122-meter high Quinshan Dam in China included an upper waterstop of corrugated rubber that spans the opening between the plinth and the face slab (Jia et al., 2000). The rubber waterstop is bolted on either side of the joint to steel angles embedded in the slab concrete, and is intended to perform the same function as the middle PVC waterstop used in other high CFRDs. This concept has also been considered for the proposed 234-meter high Shuibuya Dam in China (Jia et al., 2000).

5.6 Additional Perimeter Joint Details During the construction of CFRDs, the concrete face slab will deform and move against the plinth as the underlying rockfill settles and deforms. This deformation and movement can cause stress concentrations at the perimeter joint, and may result in spalling of the concrete or damage to the water barriers in the perimeter joint of high CFRDs. To prevent damage to the perimeter joint during construction, compressible wood or asphalt board filler is typically nailed to the butt face of the plinth in order to provide a cushion on which the face slab can rest. The filler is usually about 12 to 20 millimeters in thickness, and only functions during CFRD construction. Plywood, wood planking, or asphalt impregnated press board are commonly used.



5-15

5.7 References

Cooke, J. B., “Table of CFRD Experience” Memo No.134, 19??. Cooke, J. B., “CFRD Perimeter Joint Waterstops” Memo No. 143, 19??. Cooke, J. B., “CFRD Vertical Joint Waterstops”, Memo No. 147, 19??. Cooke, J.B., Sherard, J.L., “Concrete-Face Rockfill Dam: II. Design”, Journal of Geotechnical

Engineering, Volume 113, No. 10. American Society of Civil Engineers, October 1987. Ding, L., Zhou, X., Yang, K., Chao, H., Cui, Y., “Research on the Siltation Self-Healing

Watertight Structure for Super High CFRD,” Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Fitzpatrick, M. D., Cole, B. A., Kinstler, F. L., and Knoop, B. P., “Design of Concrete-faced

Rockfill Dams”, Concrete Face Rockfill Dams, Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.

Gomez, G. M., “Concrete Face Behavior of Aguamilpa Dam”, Concrete Face Rockfill Dams,

Proceedings, Second Symposium on CFRD, Florianopolis, Brazil, October 1999. Gratwick, C., Johanesson, P., Tohlang, S., Tente, T., and Monapathi, N., “Mohale Dam,

Lesotho”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

ICOLD, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International

Committee on Large Dams, China, September 2000. ICOLD, “Rockfill Dams with Concrete Facing-State of the Art”, International Commission on

Large Dams, Bulletin 70, 1989. Jia, J., Hao, J., Lu, X., Qu, Y., Xu, L., and Chen, X, “New Surface Water Stop System Suitable

to 100M-234M CFRD Perimeter Joint”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Jiang, G. and Zhao, Z., “High Concrete Face Rockfill Dams in China”, Proceedings,

International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Jianping, T., “Integral Model Test and Research on SR Anti-seepage and Watertight Structures

of Perimetric Joint for 230m High Concrete Faced Dam”, Proceedings, International



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Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Kashiwayanagi, M., Koizumi, S., Ishimura, Y., and Kakiage, H., “A Fundamental Study on the

Face Slab Joint Behavior of the CFRD”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Knoops, B. P., Personal Communication, April 2002. Liao, R., Xiong, Z., Zhang, Y., “Design of Water Stops at Peripheral Joint of Shuibuya Concrete

Face Rockfill Dam in China”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Mackenzie, P. R., and McDonald, L. A., “Mangrove Creek Dam: Use of Soft Rock for Rockfill”,

Concrete Face Rockfill Dams, Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.

Mauro, V., Humes, C., Luz, P. A. de C., and Alves, A. J., “Machadinho HPP – Main Dam

Design”, Concrete Face Rockfill Dams, Proceedings, Second Symposium on CFRD, Florianopolis, Brazil, October 1999.



Mori, R. T. and Sobrinho, J. A., “Application of a New Waterstop on the Concrete Face Slabs of

Ita CFRD”, Concrete Face Rockfill Dams, Proceedings, Second Symposium on CFRD, Florianopolis, Brazil, October 1999.

Morris, M. M., “Design and Construction of Terror Lake Dam”, Concrete Face Rockfill Dams,

Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985, pp. 362-378.

Pinto, N. L. de S., Filho, P. L. M., and Maurer, E., “Foz do Areia Dam – Design, Construction,

and Behavior”, Concrete Face Rockfill Dams, Design, Construction, and Performance, J.B. Cooke and J.L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.

Pinto, N. L. de S. and Mori, R. T., “A New Concept of a Perimetric Joint for Concrete Face

Rockfill Dams”, Proceedings of the 16th Congress of the International Commission on Large Dams, San Francisco, 1988, pp. 35-51.

Prusza, Z., De Fries, K., and Luque, F., “The Design of Macagua Concrete Face Rockfill Dam”,

Concrete Face Rockfill Dams, Design, Construction, and Performance, J.B. Cooke and J.L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.



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Rogers, R. L., “Boondoma Dam”, Concrete Face Rockfill Dams, Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.

Sierra, J. M., Ramirez, C. A., and Hacelas, J. E., “Design Features of Salvajina Dam”, Concrete

Face Rockfill Dams, Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985, pp. 266-285.

Tan, Jianping, “Integral Model Test and Research on SR Anti-seepage and Watertight Structures

of Perimetric Joint for 230m High Concrete Faced Dam”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

United States Army Corps of Engineers, Waterstops and Other Preformed Joint Materials for

Civil Works Structures, EM 1110-2-2102, September 1995. Wangxijiong, D. L., “Key Technical Study for Shuibuya CFRD”, Proceedings, International

Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.



6-1

Chapter 6

FACE SLAB The primary water barrier of the CFRD consists of concrete face slabs poured on underlying support zones of the rockfill body of the dam. The face slab is fully supported by the underlying rockfill, and is mostly in compression under reservoir loadings, except towards the dam abutments where tensile strains develop. Because of this, the design of face slabs in recent years has concentrated more on watertightness and durability than on strength design of the slabs, and increasing attention has been paid to identification and control of crack development in face slabs.

6.1 Behavior of Face Slabs

Understanding the behavior of face slabs is important for developing a proper design for CFRD face slabs. Giudici et al. (2000) summarized the behavior of CFRD face slabs based on their evaluation of instrumented CFRDs in Australia. Figure 6-1, taken from their report, summarizes the general behavior of face slabs under reservoir loadings. Figure 1(A) illustrates the deformation of CFRD face slabs under reservoir loadings in cross-section. As shown in the figure, deformation of the CFRD face slab will conform to the deformation of the underlying rockfill body of the dam. This fact highlights the importance of proper selection, placement and compaction of the rockfill materials supporting the face slabs to limit excessive deformations and cracking in the face slabs. Additional discussion with respect to fill materials for CFRDs is provided in Chapter 8. Figure 1(B) shows movements in the plane of the face slabs. As shown in the figure, face slabs generally move towards the center of the dam and away from the dam abutments, highlighting the fact that most slabs are generally in compression, except at the abutments. Figure 1(C) shows the movement of the face slab relative to the plinth under reservoir loadings. As shown in the figure, the face slab will tend to move away from the plinth and settle as the underlying rockfill settles under reservoir loadings. The figure as a whole illustrates that the successful performance of CFRD face slabs, in terms of providing a reasonably waterproof barrier to the reservoir, is highly dependent on factors other than the design of the face slab itself. In this respect the determination of face slab dimensions, and reinforcing is based on previous experience rather than rigorous analysis. Recent case histories, however, indicate that following precedent can lead to face deformations, face slab cracking, and high rates of leakage. Precedent can be used if, after study and analysis, the dam is expected to behave as its precedent. If deformations are expected to be different, difficulties can develop and, in that case, it is imperative that the design of the face takes into account the expected behavior of the dam instead of an idealized one. Many small details can affect the behavior of the slab. For example, at locations close to the perimeter joint, additional



6-2

reinforcement in the slab will be required if particular details exist in the embankment zoning or in the foundation that can lead to irregular face deformations and face slab cracking. Either the details are to be avoided or the slab should be heavily reinforced

6.2 Face Slab Dimensions Design of CFRD face slabs begins with the selection of slab thickness, width and location of vertical and horizontal joints. Selection of face slab thickness is typically based on previous experience, height of the dam, and minimum dimensions for proper cover of reinforcement and placement of face slab concrete. Face slab widths are typically controlled by the size of slip forming equipment and the location of the face slabs with respect to dam abutments. The location and use of vertical construction joints and vertical contraction joints depends on whether adjacent slabs are expected to move towards or away from each other under reservoir operation. The locations of horizontal joints are primarily controlled by the length of slab pours and by the geometry of starter slabs.

A B

C

ABC123

Embankment deformations under water loadMovements in plane of face slabFace displacement at perimetric jointCrest settlementFace settlementPlinth

45678

Face jointsDirection of movementsFaceFace position after water loadRockfill

2

1

5

4

3

3

7

6

8

Figure 6-1, CFRD Embankment and Face Slab Behavior Slab Thickness Modern CFRDs are supported by a well compacted, and well-graded layer of crushed rock that provides continuous support under reservoir loadings. This feature has provided CFRD designers the opportunity to use more economical face slab thicknesses. Current guidelines used for developing the thickness of face slabs for high CFRDs of compacted rockfill range from 0.3



6-3

+ 0.002H (m) to 0.3 + 0.004H (m) for CFRDs over about 100 meters high, where H is the head of water above the plinth in meters. CFRDs recently completed or under construction in China have used 0.3 + 0.003H (ICOLD 2000). For CFRDs under about 100 meters in height, a uniform slab thickness of 0.3 meters is typically used. Thinner slabs have been successfully used for CFRDs less than about 75 meters in height. Mackintosh (75 m), Bastayan (75 m) and White Spur (45 m) have a uniform face slab thickness of 0.25 m, with thickening at the perimeter joint (ICOLD 1989). The 25 meter high CFRD at Macaqua in Venezuela (Prusza et al, 1985) and the 24 meter high CFRD for the Keenleyside Powerplant Project in British Columbia both use a uniform face slab thickness of 0.25 meters with no thickening at the perimeter joint. Table 1 summarizes current practice for determining the thickness of face slabs for CFRDs.

Table 6-1

CFRD Face Slab Thickness, Current Practice Head of Water

(H) Face Slab Thickness

(t)

> 100m 0.3m + 0.002H* to 0.3m + 0.004H*

50m to 100m 0.3m < 50m 0.25m

* H = Head of water above plinth in meters

Face slabs thinner than 0.25 meters have been used in the past, such as the 0.2-meter thick slabs of the 37-meter high Kootenay Canal in British Columbia, Canada. However, practical limits to face slab thickness include the ability to properly place concrete cover and embedment requirements for reinforcing bars and waterstops, and the impact of thinner face slabs on the overall quality and performance of the constructed CFRD. Such factors should be thoroughly evaluated before thinner face slabs are incorporated into design. Pinto, 2001, and Materon, 2002, suggest that for dams up to 125 m, the formula, t = 0.3 m + 0.002H, can be used. For dams higher than 125 m, the formula, t = 0.0045H, can be used for slab thickness where H exceeds 125 m. Use of this formula will limit the hydraulic gradient across the slab to about 225. Other engineers suggest a maximum gradient across the slab of about 200 (Casinader and Rome, 1988) to limit flow through fine cracks. Casinader, in private correspondence, suggested that a face thickness of 0.30 m can be used up to a head of 67.5 m and that the following modification to Pinto’s formula could be used when H is equal to or greater than 67.5 m: t = 0.3 + (H-67.5)/225 Where: t and H are in meters.



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Panel Width Panel widths for face slabs typically range from 12 to 18 meters, with panel widths of 15 meters being common. Factors affecting the width of face slab panels are mainly related to the width of the slip forms and capabilities of concrete placing equipment. Narrower panels widths are used where vertical joints are desired due to changes in plinth geometry, rock topography, or adjacent to the dam abutments, where larger panel movements may occur. Panel widths greater than about 18 meters are uncommon. Wider panel widths can increase the occurrence of shrinkage cracks. Joints The perimeter joint, vertical joints, and horizontal construction joints are used to separate adjacent face slab panels on CFRDs. The perimeter joint separates the plinth from the face slab. Vertical joints separate adjacent panels along the axis of the dam. Horizontal joints separate different pours of the same slab, or separate starter slabs from the main face slab. The location and design of each of these joints differs according to their purpose and importance in the performance of the face slab as the water barrier of the CFRD. Perimeter Joint. The perimeter joint separates the CFRD face slab from the plinth slab. Due to its location and the movements that occur at this joint, the perimeter joint is given special consideration and is discussed in detail in Chapter 5. Vertical Expansion Joint. Vertical expansion joints are designed to allow movement between adjacent face slabs while maintaining a watertight barrier to the reservoir. They are located near the dam abutments or where two adjacent slabs have the potential to separate from each other under self-weight or reservoir loading. The design of vertical expansion joints is similar to the design of the perimeter joint on many CFRDs.

12345

Face slab reinforcementMortar padBottom waterstopUpper water barrierAnti-spalling steel for high CFRDs

4

1 2

3 5

Figure 6-2, Typical Vertical Expansion Joint (from Mohale Dam)



6-5

To allow for the anticipated movement at the expansion joint, slab reinforcement is terminated at the joint. To maintain watertightness, a single or double waterstop and joint sealing materials are typically used. A cross-section through a typical vertical expansion joint is shown in Figure 6-2. A detailed discussion of waterstops and joint sealing measures is provided in Chapter 5. Vertical Compression Joint. Vertical compression joints are located between adjacent face slabs that are not anticipated to separate away from each other. These joints are located towards the middle of the dam away from the abutments where adjacent slabs will tend to move towards each other. Reinforcement may or may not be continuous through vertical compression joints, depending on the geometry and configuration of the dam alignment. Reinforcement is not typically continued through the vertical compression joints of modern CFRDs constructed across U or V-shaped river valleys. In this situation the compressive force acting between adjacent face slabs away from the abutments keeps them in contact and acting as a single unit. For CFRDs constructed across long, flat or undulating river valleys, the force between adjacent face slabs may be compressive, neutral or possibly slightly tensile depending on the profile of the plinth along the valley floor. In these cases reinforcement is carried through vertical joints to keep adjacent slabs from separating due to changes in the plinth profile. Typically only a bottom waterstop is used to block seepage through the joint. Casinader, in private correspondence, indicates that vertical compression joints are also required when the axis of the dam is curved convex upstream, such as at Sugarloaf and Batang Ai dams. A typical vertical compression joint is shown in Figure 6-3.

Figure 6-3, Typical Vertical Compression Joint Horizontal Construction Joint. Horizontal construction joints are used when only a portion of a face slab panel cannot be poured, either by design or due to an unscheduled interruption. Reasons for horizontal construction joints include staged construction of the rockfill dam body, use of starter slabs, interruptions in slab construction due to weather or equipment malfunction, long panel lengths on high CFRDs. Horizontal construction joints typically do not incorporate any waterstops, and reinforcement is continuous through the joints. It is important to thoroughly clean and repair any honeycombing or other damage to the joint before construction of the panel is continued. A typical horizontal construction joint detail is shown in Figure 6-4. When a



6-6

bottom waterstop is incorporated into the joint design, the face of the joint is fully formed perpendicular to the slope of the dam.

1

1

5

4

2

1.4

1

12345

Face slabJoint formed normal to face above reinforcementReinforcement continuous across jointJoint greencut below reinforcement unless bottom waterstop is usedFace supporting zone

3

Figure 6-4, Typical Horizontal Construction Joint (from Mohale Dam) Face Slab Drainage during Construction Drainage of the embankment and uplift control is becoming an issue in some of the recent dams where the plinth is much deeper than the foundation of the downstream toe. Collecting wells and discharge pipes through the face may need to be left in place to allow drainage of rainwater and foundation seepage accumulated in the plinth excavation below natural drainage level. These pipes must be grouted later, when the toe buttressing fill is being placed. Alternatively, when practical, an excavated drainage channel or deepened existing channel can be used to provide gravity drainage to the downstream toe of the dam.

6.3 Crack Development in Face Slabs

Face cracks identified and studied in modern CFRDs include shrinkage cracks and structural cracks caused by a variety of mechanisms. Cracking in the starter slab of the R.D. Bailey Dam was attributed to the omission of face compaction under the slab due to a schedule interruption. The crack caused about 270 l/s of leakage, and was repaired by filling the crack with silty fine sand (Cooke, Memo No. 127). Vertical cracking in the face of Khao Laem Dam has been attributed to differential movements of the rockfill embankment near a high rock knoll in the dam foundation. These cracks resulted in about 100 l/s of leakage. The cracks were repaired by a combination of caulking and filling with silty fine sand (Cooke, Memo No. 127). Recent cracking at Khao Laem, caused by subsidence of the face support material resulted in leakage in excess of 2000 l/s (Cooke, Memo No. 178). Repairs reduced the leakage to 50 l/s (see Chapter 11 for a more detailed discussion).



6-7

Types of Cracks in Face Slabs Mori (1999) studied the development of cracks within the face slab supporting rockfill and in face slabs themselves, and grouped face cracks into three types as follows:

• Type A. These are cracks that develop due to shrinkage of the concrete slabs. These cracks are identified as relatively horizontal cracks with small widths on the order of a few tenths of a millimeter. Shrinkage cracks have been observed to extend through the thickness of the face slab, but are considered to be acceptable and are inevitable in any CFRD. Mori’s work has shown that shrinkage cracks are predominant in slabs confined by previously poured slabs on either side. Typical shrinkage cracks tend to be self- healing by calcification or clogging by silt, and no repair is necessary.

• Type B. These are structural cracks that are caused by the settlement of the underlying rockfill during and after construction. As the rockfill embankment settles, the lower portion of the embankment will tend to bulge outwards, while the upper part of the embankment will settle downward. The difference in rigidity between the concrete face slab and the CFRD rockfill causes structural stresses in the slab that induce cracking. These cracks have been observed in the middle one-third of the dam height, typically above the upstream fill buttress commonly found on newer high CFRDs. These cracks are spaced evenly at intervals of 0.5m to 1m, and are typically only a few tenths of a millimeter wide. These cracks tend to close upon reservoir filling, and do not pose a significant problem with respect to leakage. Mori reports that the total leakage through 1,200, 0.2mm wide, mapped cracks in Tianshengqiao I was estimated to be no larger than 24 l/s. Recommended treatment for open Type B cracks include treatment by fluid cement aspersions released over the slab surface above the cracks, or by covering with a rubber membrane glued over the cracks.

• Type C. Type C cracks are structural cracks caused by differential movements in the embankment either due to the effects of embankment construction in stages, or the effects of adjacent materials with very different deformation characteristics. Mori attributes Type C cracks to cracks occurring in the fine transition fill beneath the face slab that have not been properly treated prior to pouring of the face slab. The cracks reoccur in the underlying transition fill upon reservoir filling that can cause localized cracking and fissuring of the face slab in these areas. Other investigators believe that the face slab cracks are not caused by the cracks in the fill. Rather, cracks in the face slab and in the underlying fill occur because deformations are different from what was expected (Marulanda and Pinto, 2000). Even if the cracks in the fill are properly treated, once the water pressure is applied, cracks can occur in the face slab. Cracks within the fill are a consequence of deformations within the fill because of particular conditions either of the fill or the foundation. The face slab follows those movements as water load is applied. Furthermore, modern CFRDs have emphasized the need for filter protection at the perimeter joint. At that location, the zone 2A is well compacted as is the adjacent zone 2B. The result is a dense, high modulus material located within three to six meters of the perimeter joint. At distances away from the joint the face slab is supported by a less dense material, thus creating the possibility of bending stresses and face slab cracking on



6-8

the order of eight to ten meters above the perimeter joint. It has been suggested that this factor may have contributed to the face slab cracking at Ita (Pinto, 2001).

Type C cracks at the face slab near the left abutment of Xingo Dam were sometimes as wide as 10 to 15mm, and have been linked to cracks in the underlying face slab support zone according to Souza et al (1999). Cracking of the face slab support zone has been attributed to the presence of cohesive material and abrupt changes in topography that may cause differential settlements of the rockfill embankment and face slab supporting zones. At Xingo Dam cracks in the left abutment were filled with fine silty sand placed by divers underwater. Control of Face Cracks Methods to control face cracking vary according to the types of face cracks commonly found in face slabs. Type A cracking in face slabs can best be minimized and controlled by proper design of concrete mixes used in face slabs, and following proper concrete placement and curing procedures during construction. Type B cracks are more difficult to control. However, one approach suggested by Cooke (Memo No. 127) that may help control Type B cracking is to place reinforcement in thicker slabs somewhat above the centerline of the face slab thickness. For example, in face slabs where the slab thickness exceeds 0.4 m, placement of reinforcement at 200 mm below the slab surface may help reduce Type B cracking. Casinader reports, in private correspondence, that at Kotmale, reinforcement was placed at 150 mm from the top face over the entire height of the dam. Type C cracks can best be avoided by proper treatment of the rock topography and the face supporting rockfill of the dam body. Smoothing abrupt changes in rock topography beneath the face slab downstream from the plinth, and providing a sufficient cushion of rockfill between the bottom of the face slab and the top of rock will reduce cracking caused by the rock foundation. Australian practice followed for the construction of several CFRDs specified a minimum of 0.9 m of rockfill between the bottom of the face slab and the top of rock (Fitzpatrick et al., 1985). A thicker cushion of rockfill may be necessary depending on the dam height, and incorporation of vertical expansion joints and horizontal construction joints across changes in bedrock topography should also be considered. The preferred solution, however, should include the elimination of abrupt irregularities in the rock surface, thus reducing stress concentrations in the face slab. The Type C cracks observed in the face slab of Khao Laem Dam were partially caused by continuous horizontal reinforcement placed through vertical joints over the high rock knob under the rockfill embankment (Cooke, Memo No. 127). Proper selection, gradation and placement of face supporting zone materials are important in limiting the occurrence of cracks in this zone prior to construction of the concrete face slab. These issues are discussed in detail in Chapter 8. When cracks in the face-supporting zone are identified, or gaps between the concrete face and the face-supporting zone open during staged construction, they should be repaired. Cement grout mixes were used to successfully fill cracks and gaps in the face-supporting zone of the Tianshengqiao 1 CFRD prior to face slab construction. Cracks open more than 30 millimeters were filled with a fly ash and cement-sand grout mix (Wu et al., 2000). Smaller cracks were filled with a fly ash and cement grout.



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Gaps between the top of the face slab and the fill have occurred at locations between stages in face slab construction. The top of the face slab at an intermediate stage is rigid. As more fill is placed above the stage or on the downstream side of the dam, the fill deforms with the additional load, but the top of the face slab does not follow the fill. A gap develops between the face slab and the fill that can be open as much as 100 mm. The best way to avoid this problem is to construct the concrete face in one stage after the entire fill has been placed. When this construction sequence is not practical, the top of the face slab should be continuously inspected during construction so that gaps can be readily identified and repaired. Locations where gaps will tend to occur can be identified during design and additional reinforcement can be included in an effort to minimize face slab cracking. A further difficulty can occur if the concrete curb method is used to form the upstream face of the dam with no bond break between the slab and the curb. In this instance, the curb can adhere to the top of an intermediate-stage face slab. As the fill deforms away from the top of the face slab, no gap appears between the face slab and the curb, but loosening of fill and voids occur with the zone 2B adjacent to the curb, an area that cannot be easily inspected or repaired. Bond break should be applied to the face of the curb to avoid any possibility of adherence of the curb to the face slab. The concrete curb must be sufficiently weak so that the curb deforms with the rockfill and no gap occurs between the curb and the rockfill.

6.4 Concrete Properties Concrete mix design for CFRD face slabs should focus on minimizing shrinkage cracking in the face slab and increasing the durability of the concrete. Best practices followed for the production of durable and impermeable concrete for other water retaining structures should be followed for concrete face slabs of CFRDs as well. Quality control during concrete production, placement, consolidation, and curing is the most important factor in this respect. Mix Design Properties Typical 28-day concrete strengths specified for most modern CFRD face slabs range from 20 MPa to 24 MPa (3,000 psi and 3,500 psi). Higher concrete strengths require higher cement contents and increase the potential for shrinkage cracking. Shrinkage cracking is best controlled using concrete mixes with lower cement contents and using proper curing techniques. Pozzolan is commonly substituted for cement in concrete practice today, and can help reduce hydration temperatures without sacrificing concrete strength. Concrete mixes with pozzolan increases strength at older ages, increases the modulus of elasticity, and increases tensile strength, thus reducing cracks. Impermeability and resistance to adverse chemical reactions and freeze-thaw damage are important for durable concrete face slabs. Resistance to chemical reactions is achieved by proper testing and selection of cement, aggregates, and mixing water for production of concrete. Air-entrainment is the best method for producing concrete resistant to freeze-thaw damage. Limiting the water/cement ratio in the concrete mix will help produce an impermeable and durable concrete.



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Jiang and Zhao (2000) summarize research and experience in concrete mix design for high CFRDs in China. The experience in China is consistent with experience worldwide:

• Limit the water/cement ratio to about 0.50 in warmer climates and 0.45 in colder climates.

• Keep the slump of fresh concrete between 30mm and 70mm. Plasticizing agents can be introduced to improve the workability of the concrete, if necessary.

• Entrained air should be between 4-6 percent in warmer climates, and 5-7 percent in colder climates.

• Properly cure freshly poured concrete. This includes keeping the surface of freshly poured concrete slabs moist either by spraying with a mist of water or covering them with wet mats or other materials for as long as possible prior to filling the reservoir.

The introduction of concrete admixtures with expansive properties has also been reported by Jiang and Zhao to be successful in controlling shrinkage cracking in the face slabs of the Badu, Shanxi, and Qinshan CFRDs in China. Chen et al. (2000) also report success with using expansive admixtures for the construction the concrete face of the Wuluwati CFRD. Concrete Aggregates Selection of aggregates for CFRD face slabs should consider maximum particle sizes for proper concrete cover and placement and the potential for cement-aggregate reactivity. The maximum aggregate size for CFRD face slabs is generally kept under about 38mm; however, maximum aggregates sizes up to 64mm have been used successfully (Cooke and Sherard, 1987). For larger maximum aggregate sizes, special care is required when pouring concrete around construction joints and waterstops. For thinner face slabs, where the clearance between reinforcement and the surface of the concrete is reduced, keeping the maximum aggregate size to the lower limit is advisable. Although there have been no reported cases of alkali aggregrate reactivity (AAR) problems in the concrete face slabs of modern CFRDs (Cooke, 1999), aggregates for CFRD face slabs should be tested for soundness and reactivity, and the same precautions used for selection of aggregates for other water retaining structures should be used for CFRDs face slabs as well.

6.5 Reinforcing Reinforcing for CFRD face slabs usually consists of one or two mats of reinforcing bars placed at a regular spacing in the slab. Reinforcing may or may not be continuous through construction joints, and is terminated at vertical contraction joints and the perimeter joint. It is important to note that of all the types of cracking that has been observed in the face slabs of CFRDs, very few have been attributed to lack of reinforcement (i.e. low reinforcement ratios) in the face slabs. When lack of reinforcement has been suggested as a cause of face cracking, local irregularities in foundation conditions or other dam features are typically cited as the main cause. Reinforcement should be added to local areas where foundation irregularities can potentially cause bending stresses in the face slab, at the locations of intermediate stages in the face slab construction, at abrupt changes in plinth alignment, and elsewhere where specific features could



6-11

cause local stress changes. Some of these locations can be identified during design and some can be identified during construction when the foundation has been opened for inspection. All local conditions should be analyzed and reinforcement added in accordance with these conditions. This should be normal practice rather than simply using precedent. Probably not having done this is one of the reasons why problems have occurred in some dams. Reinforcement Ratios The quantity of reinforcement to be placed in the face slabs of CFRDs is typically specified by the reinforcement ratio. The reinforcement ratio is defined as the percentage of gross cross-sectional area occupied by steel reinforcement in both the horizontal and vertical directions of the face slab. Reinforcement ratios in CFRDs are typically based on past experience with dams of similar heights. Prior to the advent of CFRDs of compacted rockfill, reinforcement ratios were typically on the order of 0.5% in both the horizontal and vertical dimensions of the face slab. Since then reinforcement ratios have decreased to 0.35% in the horizontal direction and 0.40% in the vertical direction. Cooke (1999) indicates that lower reinforcement ratios have been used and are being considered for new CFRDs. He states that reinforcement ratios as low as 0.30% in the horizontal direction and as low as 0.35% or even 0.30% in the vertical direction may be considered. Reinforcement ratios are still kept to about 0.40% in both the horizontal and vertical directions within about 10 meters of the perimeter joint. A review of reinforcement ratios used in CFRDs designed and constructed in the recent past suggests a rough correlation between reinforcement ratio and the height of the CFRD. Higher reinforcement ratios are typically used in high CFRDs while lower reinforcement ratios are more common in lower CFRDs. Bar Spacing and Concrete Cover Spacing and concrete cover requirements for CFRD face slabs follow typical practice for reinforced concrete hydraulic structures. Reinforcement is usually located at the midpoint of the slab; however, alternative locations, as discussed previously, may be considered to help minimize cracking due to moment bending in areas where slabs may become stressed. Current practice typically calls for using smaller diameter bars at closer spacing to provide for increased resistance to cracking of concrete. However, bar spacing should also consider proper clearance for concrete placement and consolidation. Concrete cover is typically set at a minimum of 100 to 150 mm. Anti-Spalling Steel In high CFRDs compressive stresses at the perimeter joint can be very high during construction and prior to reservoir filling. High compressive stresses at this location can cause spalling of the concrete near the perimeter joint if movement should occur (ICOLD, 1989). To prevent spalling, additional local reinforcement is added near the waterstop at the perimeter joint, at the horizontal joint between stages, and in some cases at vertical contraction joints. This reinforcement typically consists of one or two additional layers of reinforcement above or below the center layer of reinforcement extending from the edge of the slab to a distance of 2 meters or so from



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the joint. Anti-spalling steel is not considered necessary for lower CFRDs. Compressive stresses imposed on the edges of the face slab are much lower for CFRDs under about 50 meters high, and the thinner face slabs used for lower CFRDs preclude the placement of additional layers of reinforcement. Anti-spalling steel was not used in the face slabs of the 24 meter high CFRD for the Keenleyside Powerplant Project in British Columbia. If a relatively thin slab (30 cm) is chosen, designers of several dams have widened the slab close to the plinth where relatively large movements are expected because of rockfill quality. As compression stresses at the contact with the plinth are directly related to the amount of settlement before impounding, an increase of the slab thickness (45 cm) reduces those stresses. Anti-spalling reinforcement is also included. As the slab thickness is increased, additional reinforcement is added to maintain the same steel proportion. The additional capacity to absorb bending stresses at this location is particularly favorable to deal with practical problems that have been created with the use of the concrete curb to support the face slab. The details associated with this method, Marulanda and Pinto, 2000, create the possibility of tension loading caused by the changes in deformability characteristics of the materials behind the face. Fiber Reinforcement Reinforcing bars are the standard method of reinforcement for the face slab of the CFRD; however, other types of reinforcement have been considered in recent years. Budweg (2000) evaluated the technical and economic aspects of steel fiber reinforcement for CFRD face slabs. His study considered the beneficial aspects of steel fiber reinforcement for CFRD face slabs with respect to conventionally reinforced slabs. These beneficial aspects include increased flexibility of the face slab concrete and increased resistance to crack propagation. Although material costs of conventionally reinforced concrete and fiber reinforcement are similar, fiber reinforcement is introduced directly into the concrete mix, and can provide schedule and labor cost savings since a mat of reinforcing bars does not have to be constructed and placed. Budweg indicates that a 10 to 15 percent cost savings may be realized from schedule and labor cost reductions. Fiber reinforcement for concrete face slabs has been evaluated for some new CFRDs (Jiang and Zhao, 2000); however, fiber reinforcement is still in the developmental stages for application to CFRD construction, and has not yet been used in a CFRD completed to date.

6.6 Bond between Face Slab and Concrete Curb

Marulanda and Pinto, 2000, have recommended that if the curb method is adopted at the interface between the concrete slab and the rockfill, the faces of the concrete curbs should be treated to prevent bond and reduce tensions in the concrete face, induced by rockfill deformation under water load. Ita, the first dam where the curb method was used did not use this treatment. Recent Brazilian dams, Machadinho and Quiebra Quiexa, however, have used asphalt as well as plastic sheets to prevent this bonding. Pearce, 1939, described the failure of the concrete face of the San Gabriel Dam No. 2 in California. The concrete face was constructed as a laminated slab instead of in a single slab. The slabs slipped over or under each other after settlement of the fill occurred. Similar behavior was observed on the mortar pads, built on top of the curb, at Antamina dam in Peru, for the support of



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the vertical joints. Because of this action, the entire curb surface was sprayed with an anti-bonding agent. Bond break is also discussed in Chapter 8.

6.6 References

Budweg, F. M. G., “Steel Fiber Reinforced Concrete for the Face Slab of Rockfill Dams,” Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.



Chen, M., Li, Y., Li, W., and Cao, S., “Researches on Crack Prevention Techniques of Face Slab

Concrete in Wuluwati High Concrete Faced Sandy Gravel Rockfill Dam,” Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Cooke, J. B., “The Development of Today’s CFRD Dam,” Concrete Face Rockfill Dams,

Proceedings, Second Symposium on CFRD, Florianopolis, Brazil, October 1999. Cooke, J. B., “Table of CFRD Experience” Memo No.134. Cooke, J. B., “CFRD-Face Cracks-Reinforcing” Memo No.127. Cooke, J. B., Sherard, J. L., “Concrete-Face Rockfill Dam: II. Design”, Journal of Geotechnical

Engineering, Volume 113, No. 10. American Society of Civil Engineers, October 1987. Cooke, J. B., “Khao Laem Dam Performance, 1984-2000”, Memo No. 178, June 2001. Fitzpatrick, M. D., et al., “Design of Concrete-Faced Rockfill Dams”, Concrete-Faced Rockfill

Dams, Design, Construction and Performance, J.B. Cooke and J.L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.

Giudici, S., Herweynen, R., and Quinlan, P., “HEC Experience in Concrete Faced Rockfill

Dams, Past, Present and Future”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Jiang, G. and Zhao, Z., “High Concrete Face Rockfill Dams in China”, Proceedings,

International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

ICOLD, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International

Committee on Large Dams, September 2000, Beijing.



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ICOLD, “Rockfill Dams with Concrete Facing-State of the Art”, International Commission on Large Dams, Bulletin 70, 1989.



Materon, B., “Responding to the Demands of EPC Contracts”, Water Power and Dam

Construction, August, 2002. Mori, R. T., “Deformations and Cracks in Concrete Face Rockfill Dams”, Concrete Face

Rockfill Dams, Proceedings, Second Symposium on CFRD, Florianopolis, Brazil, October 1999.

Pearce, C. E., “Discussion of Galloway, The Design of Rockfill Dams” ASCE Transactions,

Paper No. 2015, Vol. 104, 1939, pp 25-27. Pinto, N. L. de S., “Questions to Ponder on Designing Very High CFRDs”, Hydropower &

Dams, Volume 8, Issue 5, 2001. Prusza, Z., De Fries, K., and Luque, F., “The Design of Macagua Concrete Face Rockfill Dam”,

Concrete Face Rockfill Dams, Design, Construction, and Performance, J.B. Cooke and J.L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.

Souza, R. J. B., Cavalcanti, A. J. C. T., Silva, S. A., and Silveira, J. F., “Xingo Concrete Face

Rockfill Dam – Behavior of the Dam on the Left Abutment ,” Concrete Face Rockfill Dams, Proceedings, Second Symposium on CFRD, Florianopolis, Brazil, October 1999.

Wu, G. Y., Freitas, M. S. Jr., Araya, J. A. M., and Huang, Z. Y., “Planning and Construction of

Tianshengqiao 1 CFRD (China)”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.



7-1

Chapter 7

PARAPET WALL

7.1 Introduction Reduced Rockfill Volume Unlike earth core rockfill dams, concrete face rockfill dams have traditionally been provided with a concrete parapet wall at the upstream edge of the crest. A main purpose of the parapet wall is to reduce the total volume of rockfill. This is particularly true when the required rockfill is to be obtained from quarry rather than from required excavation for the dam and its appurtenant features. The volume of rockfill saved increases with the height of the dam, especially at dam sites where the valley widens downstream of the dam axis. Commonly, a single parapet wall is constructed. However, additional savings in rockfill volume can be realized by providing a double parapet wall, one at the upstream edge of the crest and another at the downstream edge. Normally, the downstream parapet wall is not as tall as the upstream wall. Increased Working space at the Crest Face slab construction requires the use of winches at the crest to support the slipforming and other equipment necessary for efficient construction. Additionally, access is required for personnel, for movement of equipment, and for delivery of concrete, steel and other material. To accommodate these activities, working space of 12 m or more is required for an efficient concreting operation. Use of a parapet wall provides a sufficiently wide working surface at the elevation of the base of the parapet wall for face slab construction, see Figure 7-1. In addition, the parapet wall serves as a wave splash barrier.

7.2 Height of Wall The design of the parapet wall has evolved over time along with the evolution of the CFRD. Early CFRDs, on the order of 50 m high, utilized parapet walls on the order of 1 to 1.5 m. As the CFRD increased in height as a result of improved compaction equipment and construction techniques, taller parapet walls, ranging in height from 4 to 8 m were adopted. To properly size the parapet wall, an economic analysis should be performed relating wall cost against the savings in cost of the rockfill. The wall cost should include the cost of concrete, reinforcement, joint treatment, and the additional costs of placing rockfill at the crest in a confined space behind the parapet wall. A list of several projects, the dam heights, and the height of the parapet wall is presented in Table 7-1.

7.3 Joint between Wall and Face Slab The joint between the parapet wall and the face slab must provide an adequate barrier against leakage from the reservoir water. Commonly, the base of the parapet wall is located somewhat above the normal maximum operating reservoir level so that the joint is not normally submerged.



7-2

During flood, the wall contains the reservoir surcharge. The elevation of the top of the wall is selected such that overtopping does not occur during the probable maximum flood.

Table 7-1 Height of Parapet Wall

Dam

Dam Height, m

Parapet Wall Height, m

El Pescador 43 5 Shiroro 125 4 Golilas 125 7

Khao Laem 130 5 Mohale 145 7.5

Salvajina 148 8 Areia 160 6

Aguamilpa 185 8 Shuibuya 233 9

Minimum joint treatment consists of a water stop in the middle or at the base of the joint and a mortar pad at the base of the joint to provide support. Mastic filler is often used above the water stop. If the vertical face slab joint contains both a middle water stop and a water stop at the base, it is common practice to place middle and base water stops within the parapet-wall/face-slab joint. Current trends are to use a vertical joint instead of a joint perpendicular to the plane of the face slab. The vertical joint is easier to construct and avoids the difficulty of placing concrete against an overhung form. In addition, a vertical joint is somewhat easier to maintain. Design of the joint should avoid “feather-edging” at the exposed surface of the joint. At Cirata dam in Indonesia, a crack formed as a result of the feather edge that by-passed the water stop placed within the joint, Casinader, private correspondence. In addition to proper joint design, good quality construction of the wall, the joint, and the supporting fill adjacent to the joint is equally important in assuring adequate performance of the parapet wall and its joint with the face slab. At the 71 m high Gouhou Dam in China, when the reservoir water level rose during flood, reservoir water passed through the joint (Jiang and Zhao, 2000). The leakage resulted in piping of the support material into the coarser graded body of the dam. The end result was failure of the dam. Upon investigation and inspection of the joint, poor quality construction of the joint was found to have contributed to the leakage and failure. Also, contributing to the failure was the inadequate grading of the several fill zones of the dam.

7.4 Transverse Joints Transverse construction joints are spaced to coincide with the vertical joints in the face slab. These joints are commonly spaced every 15 m, or are spaced at half the face slab width. Soft joint filler, such as a bituminous fiber material, is provided to accommodate post-construction



7-3

settlement and movement associated with temperature variations. A continuous water stop is provided in the middle of the wall and at the base of the upstream heel. The water stop connects to the water stop at the base of the parapet/face slab joint. This provides continuity of the water stop from the transverse wall joints to the parapet/face slab joint. A polysulphide joint sealant is commonly provided on joint surfaces exposed to the weather or to the reservoir.

7.5 Abutment Details

Rockfill at the crest of the dam is usually placed to within 1.5 to 2 m of the top of the parapet wall. The road on the crest of the dam continues to the abutments and normally connects to project access roads. This requires a gradual slope transition, normally 10% (maximum 15%), from the level of the dam crest to the top elevation of the parapet wall at the abutment. Commonly, an abutment wall detail is developed to connect the CFRD to the abutments. The geometry of this detail is dependent on the topography and foundation conditions at top of the dam and the connection requirements imposed by adjacent structures such as a spillway.

7.6 Crest Width The crest width for the CFRD varies depending on its use, on the necessity to accommodate construction equipment, and on the height of the dam. The crest must accommodate anticipated traffic that can range from modest traffic for maintenance and operation to heavy traffic for a major public highway. Modern slip form equipment for face slab construction requires a width of about 20 m at the base of the parapet wall. This requirement affects crest geometry and crest width. Current practice is to select a crest width of 8 to 10 m for dams of up to 150 m high and 10 to 12 m for dams taller than 150 m. The crest and parapet geometry for the 145-m tall Mohale Dam is shown in Figure 7-1.

7.7 Case Histories Kangaroo Creek, Australia The Kangaroo Creek Dam, constructed in 1968, was initially built to a height of 60 m using weak rock (schist) from the site instead of traditionally accepted practice of using durable rock. The dam was constructed with a crest width of six meters and a one-meter high parapet wall at the upstream edge of the crest. Twenty years later, the dam was raised by 4.6 m by constructing a reinforced concrete open box structure backfilled with compacted rockfill. The final crest width of the raised dam was reduced to 4.7 m (see Figure 7-2). A difficulty that can arise with this concept, is that the downstream edge of the crest is poorly compacted. This location is most heavily loaded during high reservoir levels.



7-4

Golillas, Colombia The 125 m high Golillas Dam consisted of alluvial gravel fill for the main dam embankment instead of rockfill. The dam has a crest width of 8 m and a 7 m high parapet wall. The base of the parapet wall extended over the entire width of the dam crest and was anchored into the dam fill using post-tensioned tendons. The joint between the base of the wall and the face slab is perpendicular to the face slab. The joint treatment is similar to the perimeter joint, i.e. copper waterstop at the base, PVC waterstop in the middle and membrane covered mastic (Igas) at the top of the joint. Figure 7-3 illustrates the crest geometry.

Figure 7-1. Crest Detail, Mohale Dam, Lesotho



7-5

Figure 7-2. Crest Detail, Kangaroo Creek, Australia

EL 2995.00

EL 2988.00

8 m

7 m

Concrete face

Post-tensioning tendons

DamCL

Figure 7-3. Crest Detail, Golillas Dam, Colombia

Salvajina, Colombia The main embankment material for the 148 m high Salvajina CFRD is compacted gravel. The fill volume was reduced substantially by using an 8 m high parapet wall at the upstream edge of the crest and a 2.6 m high wall at the downstream edge (see Figure 7-4). A one-meter-wide heel on the upstream parapet wall was used to provide access to monitoring. Current practice is to use a parapet wall similar to that at Salvajina with a heel for access and a vertical joint between the parapet wall and the face slab.



7-6

EL 1159.0 m

EL 1161.6 m

EL 1155.0 mEL 1154.0 m

EL 1162.0 m

1.3-1.41

8 m

1 2

43

1234

Face slabCompacted semi-pervious materialCompacted gravelCompacted rockfill

Dam

Figure 7-4. Crest Detail, Salvajina Dam, Colombia Aguamilpa, Mexico Aguamilpa dam, located in the western part of Mexico, is a 187-m-tall CFRD. The main body of the embankment consists of compacted alluvial gravel in the upstream half and compacted rockfill in the downstream. A substantial portion of the embankment is founded on alluvial sands and gravels. The dam has a crest width of 8 m, expanding to 10 m, and is provided with two parapet walls on the crest, a 6 m high wall at the upstream edge and a 4 m high wall at the downstream edge. Maximum reservoir water level is allowed to rise above the base of the joint between the face slab and the base of the parapet wall. The geometry of the parapet wall is shown if Figure 7-5.

11.5

EL 233.03 m

EL 230.00 mEL 229.63 m

EL 232.00 m

EL 235.00 m

EL 232.23 m

Base coursematerial for road

Road

Figure 7-5. Crest Detail, Aguamilpa, Mexico El Pescador El Pescador dam, 43 m high, is located in the Valle del Cauca region in Colombia, it was



7-7

finished in 2002. The fill is mainly composed by compacted rockfill (diabase). The single parapet wall, 5 m. high, is placed at the upstream edge of the crest between elevations 1408 and 1413. After the completion of the parapet the fill was raised to elevation 1412. The parapet has vertical joints each 15 m along the crest, aligned with the joints between the slabs in the concrete face. Figure 7-6 illustrates the geometry of the crest.

Figure 7-6. Crest Detail, El Pescador Dam, Colombia

7.8 References Amaya, F. and Marulanda, A., “Golillas dam – Design, Construction and Performance”,

Concrete Face Rockfill Dams-Design, Construction and Performance, J. B. Cooke and J. L. Sherard, Editors, ASCE, pp. 98-120, Detroit, October 1985.

Good, R. J., Bain, D. L. W., and Parsons, A. M., “Weak Rock in Two Rockfill Dams”, Concrete

Face Rockfill Dams-Design, Construction and Performance, J. B. Cooke and J. L. Sherard, Editors, ASCE, Detroit, October 1985.

Guocheng, J., and Zengkai, Z., “High Concrete Face Rockfill Dams in China”, Proceedings,

International Symposium on Concrete Faced Rockfill Dams, pp 1-20, Bejing, China, September 2000.

Montanez-Cartaxo, L. E., Hacelas, J. E., and Castro-Abonce, J., “Design of Aguamilpa Dam”,

Proceedings, International Symposium on High Earth-Rockfill Dams (Especially CFRD), Volume I, pp 337-364, Bejing, China, October 1993.

Sierra, J. M., Ramirez, C. A. and Hacelas, J. E., “Design Features of Salvajina Dam”, Concrete

Face Rockfill Dams-Design, Construction and Performance, J. B. Cooke and J. L. Sherard, Editors, ASCE, pp. 266-285, Detroit, October 1985.



8-1

Chapter 8

EMBANKMENT ZONES AND PROPERTIES For many early CFRDs, a thin zone of massive, crane-placed, dry masonry provided support for the concrete face. This practice was abandoned when rockfill started to be placed and compacted in layers. Prior to Cethana dam the practice had been to exclude fines (particles less than 50 mm) in order to provide a material consisting entirely of coarse rock particles so that rock to rock contact would be guaranteed and, if the face leaked, there would be no possibility of fines washing out with consequent settlement and loss of support under the concrete face, causing cracking. Zoning of the dam and the functions of the various zones have gradually evolved over the years to the present. The following discussion of materials, their functions, and their gradations is meant to provide the current state-of-the-practice and to aid the dam designer in selecting appropriate material characteristics for the several zones of the CFRD.

8.1 Zoning of the CFRD The zoning of the CFRD and the numerical designation of the zones, as suggested by Cooke (1988), are illustrated on Figure 8-1. In many countries, these zone designations are standard. A brief description follows: • Zone 1A: Fine-grained cohesionless silt and fine sand with isolated gravel and cobble sized

rock particles up to 150 mm. The zone should be cohesionless so that brittle cracking does not occur. The zone should be placed in 200 to 300 mm layers and lightly compacted. The zone serves as a source of material that, if required, can migrate through cracks in the face slab. In addition, at recent projects, a zone or pocket (less than 1 m3/m of perimeter joint) of non-cohesive silt or fly ash has been placed over the top of the perimeter joint to provide an easily erodible material at this critical location. This is discussed in more detail in Chapter 5, Perimeter Joint.

• Zone 1B: Random mix of silts, clays, sands, gravels, and cobbles to provide support to Zone 1A. The zone should be placed in 200 to 300 mm layers and compacted.

• Zone 2A: Sand and gravel filter located within two to three meters of the perimeter joint. In the event of disruption of the waterstops at the perimeter joint, the filter zone 2A will prevent the movement of silt size particles through the zone and, thus, serves as secondary defense against leakage. This zone consists of material equal or nearly equal in quality to concrete aggregate. The material is manufactured and processed to specific gradation limits. Zone 2A should be placed in 200 to 400 mm layers, well-compacted with vibratory compactors, and protected from damage and erosion during construction. The requirements of this material are discussed in more detail in this chapter. Modern CFRDs have emphasized the need for filter protection at the perimeter joint. At that location, the zone 2A is well compacted as is the adjacent zone 2B. The result is a dense, high modulus material located within three or more meters of the perimeter joint. At distances away from the joint the face slab is supported by a less dense material, thus



8-2

creating the possibility of bending stresses and face slab cracking on the order of eight to ten meters above the perimeter joint. Some engineers have suggested that this factor may have contributed to the face slab cracking at Ita (Pinto, 2001). It is well known that only a few centimeters of material are required to provide a filter. The filter 2A should be restricted to perhaps one to two meters instead of three meters as is commonly specified.

• Zone 2B: Zone 2B provides support to the face slab and consists of sand and gravel-sized particles, placed in 400 mm horizontal layers and normally compacted with 4 passes of a 10-ton smooth-drum vibratory roller. The horizontal width of the zone varies from 2 to 4 m depending on the height of the dam. This zone consists of material equal or nearly equal in quality to concrete aggregate. The material is a crushed product and manufactured to specific gradation limits. The requirements of this material are discussed in more detail in this chapter.

• Zone 3A: This zone is a transition between Zone 2B and rockfill Zone 3B and consists of rockfill with maximum size of 400 mm or less placed in 400 mm layers and normally compacted with at least 4 passes of a 10-ton or heavier smooth-drum vibratory roller. The horizontal width of the zone varies from 2 to 4 m depending on the height of the dam. The material may be select rockfill from the quarry or may be a crusher-run minus 200 or 300 mm product, if the supply of select rockfill from the quarry is insufficient or inconsistent. In Australia, this zone is designated Zone 2C and is designed to act as a transition between Zone 2B and coarser rockfill zones downstream. It is therefore a material that should meet filter criteria. Processing of material, such as passing the material over a grizzly to exclude the larger rock particles, is likely to be required.

• Zone 3B: This zone commonly consists of rockfill with maximum size of 1000 mm placed in 1000 mm layers and normally compacted with 4 passes of a 10-ton smooth-drum vibratory roller. For some projects, final decisions concerning the appropriate number of passes are made after conducting tests in which the average surface level of the rockfill layer is determined by surveying at intervals of 2 to 12 passes. Water (10%-25% of rock volume) is added during fill placement. Increasing compaction coverage, using thinner layers, and application of water are means of achieving satisfactory density when using weak rock. Thinner layers are often used for sand and gravel fills, 600 mm layers were used at Aguamilpa.

• Zone 3C: This zone commonly consists of rockfill with maximum size of 2000 mm placed in 2000 mm layers and normally compacted with 4 passes of a 10-ton smooth-drum vibratory roller. As for Zone 3B, layer thickness and compaction effort are adjusted based on the characteristics of the material.

• Zones 3D, 3E, etc (not shown in Figure 8-1): These rockfill zones provide positive drainage within the embankment. In well-drained rockfill embankments, this zone or zones are placed at the base of the dam within the valley section. In poorly drained rockfills or in fills consisting of sands and gravels, these drainage zones may consist of a continuous chimney or wall drain and a high capacity underdrain at the base of the dam. High capacity internal drainage is a key safety feature of the CFRD.

The embankment of the CFRD may consist of hard strong basalts, granites, greywackes and dolomites; or the softer, weaker claystones, siltstones, sandstones, and poorly cemented



8-3

limestones; or alluvial sands, gravels, cobbles and boulders. The requirements for material processing, layer thickness, compaction, and internal drainage are functions of the characteristics of the proposed borrow and/or quarry sources. Compatibility should be achieved at zone interfaces by specifying layer thickness in multiples of each other, such as,

• Zone 2A, 200 mm,

• Zones 2B and 3A, 400 mm, and

• Zone 3B, 800 mm for about 10 m adjacent to the interface with 3A. Downstream slope protection is simply specified. Large rock are dozed to the downstream face and shaped with a backhoe to the line and grade of the downstream slope as construction proceeds.

8.2 Filter (Zone 2A) Filter Requirements In earth and earth-rock dam design, the importance of filters placed at the downstream face of the earth core or within a chimney drain system has long been recognized (ICOLD, 1994). The filter-drain system provides an all-important second line of defense. If the waterstops at the perimeter joint are disrupted such that reservoir leakage through the joint occurs, the 2A filter must retain silt and fine sand particles. High head loss will occur through the clogged filter interface and/or through the silts and sands trapped within the joint upstream of the filter. In addition, the filter must be considerably more permeable than the clogged interface or the material trapped in the joint. The following criteria summarize these fundamental functions (ICOLD, 1994): 1. Retention function: The classic Terzaghi criterion D15/d85 < 4 addresses this

requirement. In this expression the following symbols are used: .

D15 = particle size in filter (protecting, or coarser material) for which 15% by weight of particles are smaller; and

d85 = particle size in base (protected, or finer material) for which 85% by weight

of particles are smaller. 2. Permeability function: The classic Terzaghi criterion D15/d15 > 4 addresses this

requirement. It is noted that strict adherence to this criterion with respect to Zones 2A and 2B is not required.



8-4

Figure 8-1, CFRD Rockfill Zoning To achieve the above functions, the Zone 2A filter (ICOLD, 1994): • Should not segregate or change in gradation (degrade or break down) during processing,

handling, placing, spreading or compaction. • Should not have exhibit cohesion or the ability to cement as a result of chemical, physical or

biological action. Vaughan (1982) suggested the use of the "sand castle" test for cohesion:



8-5

"A simple test, suitable for use in a field laboratory, has been devised to examine filter cohesion. It consists of forming a cylindrical or conical sample of moist compacted filter, either in a compaction mould, or in a small bucket such as is used by a child on a beach; standing the sample in a shallow tray (if a bucket is used the operation is exactly as building a child's sand castle) and carefully flooding the tray with water. If the sample then collapses to its true angle of repose as the water rises and destroys the capillary suctions in the filter, then the filter is noncohesive. Samples can be stored for varying periods to see if cohesive bonds form with time. This test is, in effect, a compression test performed at zero effective confining pressure and a very small shear stress, and it is a very sensitive detector of a small degree of cohesion."

• Should be internally stable, that is, the coarser fraction of the filter with respect to its own

finer fraction must meet the retention (piping) criterion Filters for Earth and Earth-Rock Dams The research and criteria currently in use for the design of earth and earth-rock dams is pertinent to the design of the Zone 2A filter for the CFRD. As a result of the research by Dr. James Sherard and the US Soil Conservation Service in the 1980s (Sherard et al, 1984a, 1984b, 1985, 1989), considerable attention is paid to the selection of the gradation of filters for earth and earth-rock dams. The design criteria presented in Tables 8-1 and 8-2, ICOLD 1994, is now used by the US Soil Conservation Service, the US Bureau of Reclamation and the US Army Corps of Engineers (USDA SCS, 1986; USBR, 1987; USCOE, 1994). Gradation for CFRD Zone 2A The gradation of the material utilized for zone 2A for Aguamilpa (Zone 2F) is shown on Figure 8-2. Several differences are apparent between the gradations of typical fine filters for earth core rockfill dams and typical zone 2A gradations for CFRDs:

• The percentage of plus 3/4-inch material is considerably larger for the zone 2A in the CFRD, ie, 20 to 40% vs 0 to 15% for the fine filter in earth core dams.

• The percentage of sand size material is smaller for the zone 2A in the CFRD, ie, 30 to

60% vs 55 to 80 or 90% for the fine filter in earth core dams.

• The percentage of minus #200 sieve material is considerably larger for the zone 2A in the CFRD, ie, 5 to 10 or 12% in the CFRD vs 0 to 5% for the fine filter in earth core dams. The larger quantity of fines, especially above 10%, reduces the permeability by a factor of 100 or possibly more and will cause the material to exhibit cohesion. Tests performed for the Aguamilpa Zone 2F (Zone 2A) indicate a permeability of 7X10-5 cm/s, a hundred or more times lower than the typical fine filter for an earth core dam.



8-6

Table 8-1 Criteria for Filters (ICOLD, 1994; USDA SCS, 1986; USBR, 1987a; USCOE, 1994)

Base Soil Category

Base Soil Description, and Per-cent Finer than No. 200 (0.075

mm) sieve (note 1/)

Filter Criteria (note 2/)

1

Fine silts and clays; more than 85% finer

D15 < 9 x d85 (note 3/)

2

Sands, silts, clays, and silty and clayey sands; 40 to 85% finer

D15 < 0.7 mm

3

Silty and clayey sands and

gravels;15 to 39% finer

( )D A xd mm mm15 85 5

4040 15 4 0 7 0 7≤ +

−−

− . . ,notes4

4

Sands and gravels; less than 15% finer

D15 < 4 x d85 (note 6/)

1/ Category designation for soil containing particles larger than the #4 sieve (4.75 mm) is

determined from a gradation curve of the base soil which has been adjusted to 100% passing the No. 4 (4.75 mm) sieve.

2/ Filters are to have a maximum particle size of 75mm (3 inches) and a maximum of 5% passing the No. 200 (0.075 mm) sieve with the plasticity index (PI) of the fines equal to zero. Note that the criteria relating the D90 to the D10 shown on Table 8-2 below must be used to design the filter gradation ranges. These criteria force the designer to use uniform filter gradations that help to prevent segregation during placement. PI is determined on the material passing the No. 40 (0.425 mm) sieve in accordance with ASTM-D-4318. To ensure sufficient permeability, filters are to have a D15 size equal to or greater than 4 x d15 but no smaller than 0.1 mm.

3/ When 9 x d85 is less than 0.2 mm, use 0.2 mm. 4/ A = percent of base material passing the No. 200 (0.075 mm) sieve after any regrading. 5/ When 4 x d85 is less than 0.7 mm, use 0.7 mm. 6/ In category 4, the d85 may be determined from the original gradation curve of the base soil

without adjustments for particles larger than 4.75 mm.



8-7

Table 8-2 D10f and D90f Limits to Prevent Segregation (ICOLD, 1994; USDA SCS, 1986; USBR, 1987)

Minimum D10

mm

Maximum D90

mm

<0.5

20

0.5 - 1.0

25

1.0 - 2.0

30

2.0 - 5.0

40

5.0 - 10

50

10 - 50

60

Because of the larger percentage of coarse particles (+3/4 inch) and the larger percentage of fines (-#200) in the typical zone 2A for CFRDs, the material is more susceptible to segregation during placement than the typical earth core fine filter. Segregation occurs more readily at the outer edges of the zone. The important retention criterion is met by the Aguamilpa gradation unless segregation occurs. An alternative gradation for Zone 2A is shown on Figure 8-2 and in Table 8-3, along with the Aguamilpa gradation. This alternative gradation limits the percentage of plus 3/4-inch material to 0 to 15%, includes a generous percentage of sand size particles, 50 to 75%, and limits the percentage of fines passing the No. 200 sieve to 0 to 5%. In addition, the alternative gradation is more uniform, the Uniformity Coefficient, D60/D10, of the Aguamilpa average gradation is 10/0.13 = 77, whereas the Uniformity Coefficient of the average alternative gradation is 3.6/0.18 = 20. The Zone 2A for the 140-m tall Mohale Dam in Lesotho is modeled after the alternative gradation. The alternative gradation will not segregate during placement, the fines content will provide some binder for stability during placement and the permeability will be about the same as for the typical fine filter for the earth and earth-rock dams, in the range of 10-2 cm/s. The material will not exhibit cohesion. The D15 size of the material will range from about 0.15 to 0.6mm. This will result in an excellent filter for fine sand and silt size material. The gradation of concrete sand, ranging from about 10 mm to a limit of 2 to 10% on the #100 sieve (0.15 mm), is an acceptable alternative for use as Zone 2A.



8-8

100

90

80

70

60

50

40

30

20

10

0

0

10

20

30

40

50

60

70

80

90

1001000 100 10 1.0 0.1 0.01 0.001

3 in 3/4 in No. 4 8 16 30 50 100 200U.S. Standard Sieve

Perc

ent f

iner

by w

eight Percent retained

Grain size in millimeters

Gravel Sand Silt ClayCoarse Fine Coarse Medium Fine

Figure 8-2, Zone 2A Gradations

Table 8-3 CFRD Gradation Limits for Zone 2A

Percent passing, by weight US Standard Sieve

Size in mm Aguamilpa

Mexico (Zone 2F) Alternative Gradation

1 ½ “ 38.1 100 100 ¾” 19.1 60-80 85-100

No. 4 4.76 32-60 50-75 No. 16 1.19 20-43 25-50 No. 50 0.297 12-26 10-25 No. 200 0.074 5-12 0-5

8.3 Face Slab Support Material (Zone 2B) The grading of the material underlying the concrete face, Zone 2B in Figure 8-1, has been changing as construction experience has been gained, and design has progressed. The change has been to use a smaller maximum size and more fines, i.e., greater content of particles finer than 4.76 mm and 0.074 mm (No. 4 and 200 sieves). The gradations with maximum size of 250-



8-9

330 mm and minimum size of 50-75 mm were unsatisfactory because of severe segregation. After face compaction the surface rocks loosened readily as a result of construction activity. The exterior surface could not be formed to a smooth plane and excess concrete was common. ICOLD Bulletin 70 Recommendation, 1989 The recommended gradation for the face slab support material, as presented in ICOLD Bulletin 70, is shown in Table 8-5:

Table 8-5

Bulletin 70 Gradation Limits for Zone 2B

US Standard Sieve

Size in mm

Percent passing, by weight

3” 76.2 100 1 ½ “ 38.1 70-100 ¾” 19.1 55-80

No. 4 4.76 35-55 No. 30 0.59 8-30 No. 200 0.074 5-15

The aim of the Bulletin 70 specification is to limit maximum size, to provide a grading which will not segregate during placement, and to include sufficient fines to give an acceptable low permeability. A target permeability of 1X10-4 cm/s is recommended. Typically, the following is specified: a maximum size between 76 mm and 38 mm, 35% to 55% finer than 4.76 mm (No. 4 sieve) to assure that the average material will have at least 40% sand size particles, and 5% to as much as 15% passing the No. 200 sieve. This gradation exhibits low permeability and some cohesion. Because of the brittle nature of the material, open cracks can appear when deformations take place within the rockfill zones during construction. This occurred at Xingo Dam in Brazil (Marulanda and Pinto, 2000) and at Tianshengqiao Dam (TSQ1) in China (Mori, 1999). Xingo. At Xingo, the gradation of Zone I (Zone 2B) included 10 to 15% minus #200 sieve material and 35 to 55% sands. During fill placement, cracks in the surface of Zone I were observed, close to the left abutment. Cracks had an average width of 20 mm but some were as wide as 56 mm and were essentially vertical. Offsets of the order of 15 mm were reported. Initially the cracks were sealed on the surface with mastic and fill placement resumed. New openings within the same cracks occurred as well as new cracks at higher elevations in the same zone. Prior to the placement of the face slab, cracks were filled with sand; the surface was re-graded and compacted with a vibratory roller.



8-10

Cracks at Xingo were explained by the differences in deformation characteristics between the several zones. Modulus of deformation, as calculated by measured settlement, indicated a value of 68 MPa for Zone III (Zone 3B) and only 24 MPa for Zone IV (Zone 3C). During construction, the rockfill within the valley section settled under the overlying rockfill load. This downward movement at the maximum section causes the rockfill at the abutments to settle toward the valley section creating tensile stresses within the abutment rockfill zones. The granular, non-cohesive, rockfill zones readily accept these deformations without distress. The brittle, high-fines content face support material Zone I (Zone 2B) could not accept these deformations without cracking.

Settlements and deformations at Xingo continued within the rockfill zones after reservoir filling. Normal behavior was reported during the first 1.5 years with leakage on the order of 110 l/s. Subsequently, the rate of settlement of several instruments increased significantly over a period of about six weeks, then returned to similar rates recorded prior to the increase. Leakage increased to rates ranging from 180 to 200 l/s. Diver inspections indicated major cracks in the same areas where cracks had occurred in Zone I (Zone 2B) during construction. At one location, an 8-m long crack, 15 mm wide, was detected and an offset of about 300 mm was observed between two slabs. The on-going settlement and the increase in leakage were closely related (Sousa, 1999). Initial cracking of the face slab was probably the result of the same behavior that explained the cracks in Zone I (Zone 2B). Leakage penetrated the dam fill reaching layers of less pervious material where rockfill with higher fines content was placed. It is believed that the increased rates of settlement were caused by wetting and saturation as a result of the increased leakage in this area. The increased settlement caused cracks to open further. Most probably, cracks in the Zone I material opened again allowing increased leakage. Re-opening of cracks also explains why the complete sealing after dumping of dirty sand was not obtained. Tianshengqiao. At the 180-m high TSQ1 Dam in China the face support material, Zone IIB (Zone 2B) has a maximum size of 80 mm and a fines content ranging between 10 and 15%. The embankment was raised in seven stages by adding rockfill to the downstream slope of the dam. The face slab was constructed in three stages. Mori, 1999, reports that several vertical cracks were observed in Zone IIB with depths of the order of 3 m and as wide as 100 mm when additional fill was placed in subsequent stages on the downstream slope of the dam. Cracks 30 mm wide and 3 to 4 m deep were filled with a grout mix of 10% cement and 90% fly ash. Cracks wider that 30 mm were filled with a grout mix consisting of 5% cement, 35% fly ash, and 60% sand. An additional layer of reinforcing steel was placed below the main reinforcement in the area where the cracks were observed. Face slab reinforcement was increased for the third concrete stage. Modified ICOLD Bulletin 70 Gradation Placing a brittle material, with high fines content, in Zone 2B that can crack during construction and which may re-open during project operation should be avoided. Cracks that open or re-open during project operation can lead to face slab cracks in the same general locations as additional deformations take place. In order to avoid cracks, the zone must be completely non-cohesive so that when deformations occur, the Zone 2B material will accommodate the movements without



8-11

cracking. A crushed, processed good quality (approaching the quality of concrete aggregate) material with a maximum size of 80 mm, 40 to 50% passing the No. 4 sieve, and a maximum of 5% non-cohesive fines is recommended. The modified Bulletin 70 gradation for the face slab support material is shown in Table 8-6 and in Figure 8-3: The material should be manufactured by crushing, screening and washing as required to obtain a well-graded material with all particle sizes represented. Gap grading as might be produced by blending crushed rock with natural sand should be avoided. With care, this material will not segregate (although it does not meet the criterion presented in Table 8-2) during placement and will compact easily with 4 passes of the 10-ton vibratory roller. The permeability of the material, when compacted, will normally exceed 10-2 cm/s. If cohesive fines are used, the material will be less permeable and may exhibit the ability to crack. The main difference between the modified gradation for Zone 2B and the Bulletin 70 gradation is the percentage of fines passing the No. 200 sieve.

Table 8-6

Modified Bulletin 70 Gradation Limits for Zone 2B

US Standard

Sieve

Size in mm

Percent passing, by weight

Modified Gradation

Limits, Zone 2B

Antimina Peru

El Pescador Colombia

3” 76.2 100 100 90-100 1 ½ “ 38.1 70-100 80-100 70-100 ¾” 19.1 55-80 60-85 55-80

No. 4 4.76 35-60 40-55 35-55 No. 16 1.19 18-40 22-35 20-40 No. 50 0.297 6-18 10-20 0-22 No. 200 0.074 0-7 (non-

cohesive) 5-7 0-8

R. J. Casinader, 2002, suggests that the “braking” function of Zone 2B can be achieved using the following gradation:

• 80 mm 100% passing • 4.76 mm (#4 sieve) 30 to 50% passing • 0.074 mm (#200 sieve), non-cohesive fines 2 to 10% passing

This is an acceptable gradation provided segregation does not occur during placement and cracking does not develop with subsequent deformation of the rockfill. Vaughn’s “sand castle” test, outlined previously, can be used to determine whether the material is non-cohesive. Often,



8-12

a material with as much 10% passing the #200 sieve will exhibit cohesion and will support open cracks.

100

90

80

70

60

50

40

30

20

10

0

0

10

20

30

40

50

60

70

80

90

1001000 100 10 1.0 0.1 0.01 0.001

3 in 3/4 in No. 4 8 16 30 50 100 200U.S. Standard Sieve Size

Perc

ent f

iner

by w

eight

Percent retained

Grain size in millimeters

Gravel Sand Silt ClayCoarse Fine Coarse Medium Fine

Figure 8-3, Modified Zone 2B Gradation

Crusher-run minus 3” Material Crusher-run minus 3” material has been specified for the face support material for many CFRDs. When hard, competent basalt or granites are used, the resulting gradation contains less than 5% fines and between 10 and about 25% sand passing the No. 4 sieve. The range of gradations for Zone 2B for the 145-m high Mohale CFRD (hard strong basalt) and the 20-m high Keenleyside CFRD (hard strong granite) are presented in Table 8-7. The above materials, when placed, exhibit a coarse granular appearance with some segregation. This is the result of the relatively small percentage of sand-sized material. At Keenleyside, the material was used for the face support zone for the CFRD and for the underdrain for the concrete lining of the approach channel. Permeability of the test gradation, as presented in Table 8-7, was measured in the field using the test setup shown on Figure 8-4. Tests were needed because the material serves the dual purpose of face support and a high capacity drain. Material for the test was placed in the test setup in horizontal layers, simulating the placement in the field. The measured permeability of the material ranged from 1 to 2 cm/s. Materon, 1998, presents a summary of the characteristics of the Zone 2B face support material at a number of dams worldwide. Brazilian experience is summarized in Table 8-8 below:



8-13

Table 8-7

Gradation of Crusher-run Minus 3” hard, strong Basalt and Granite

Percent passing, by weight US Standard Sieve

Size in mm Mohale

Lesotho Keenleyside

British Columbia Measured

Gradation Target

Gradation Average

Gradation Test

Gradation 3” 76.2 100 100 100 100

1 ½ “ 38.1 70-90 60-95 78 92 ¾” 19.1 30-55 30-65 36 60

No. 4 4.76 8-25 8-35 15 22 No. 16 1.19 3-17 3-20 10 12 No. 50 0.297 1-10 0-10 6 8

No. 200 0.074 0-5 0-5 3 4

Table 8-8

Characteristics of Zone 2B, Brazilian CFRDs (Sobrinho, et al, 2000)

Dam Fox do Areia

Segredo Itá Xingó Machadinho

Itapebi

Fill Type Crushed Sound Basalt

Crushed Sound Basalt


Grizzlied Sound and Weathered

Granite/Gneiss


Processed Gneiss

Max. 4"

Width at base, m 13 8 10 12 10 12 Width at crest, m 4 5 3 + 4 4/6 3 + 4 3 + 4 Layer thickness, mm 400 400 400 400 400 400 Gradation: Max. particle size, mm 25.4mm, % passing # 4 sieve, % passing # 100 sieve, % passing # 200 sieve, % passing

100 50 12 1 0

75 45 20 2 0

75 60 25 5 1

100 70 44 10 7

75 50 15 7 2

100 80 45 11 7

Compaction: Horizontal surfaces (passes/roller) Upslope (passes/roller)

4/10 ton vibratory

6 passes

4/10 ton vibratory

4/static +

6/vibratory

4/9 ton vibratory

extruded wall

6/9 ton vibratory

4/static +

6/vibratory

4/10 ton vibratory

extruded wall

4/9 ton vibratory

extruded wall

Void Ratio 0.31 0.21 0.175 0.31 0.19 Density, kN/m3 21.2 22.7 21.5 21.2 19.7 22.0 Performance During Construction

Adequate

Adequate

Adequate

Cracking + Settlement

Under Construction

Under Construction



8-14

540 φ 50mm screen (typical each end)

Pipe filled with drain rock 90° weir (150 deep)

As-built Test Setup - Longitudinal Section Not to Scale

Dimensions in mm

Cross Section A-A Not to Scale

Place and compact drain rock in 100 mm horizontal lifts

5 mm steel plate 10 mm neoprene gasket

A

A

Figure 8-4, Keenleyside, Permeability Test Setup Surface Protection during Construction Surface protection of Zone 2B is needed to prevent erosion during heavy rains and to provide a firm base to assemble the reinforcing steel and forms. Asphalt, shotcrete, and mortar coatings have been used successfully on a number of CFRDs (Materon and Mori, 2000). The asphalt surface protection is usually applied in two passes, the initial pass consisting of a penetrating mix, and a second thicker mix to serve as bedding for the slab. Prior to applying the surface protection, the surface is shaped and compacted with a vibratory roller or face vibratory compactor. If the material for Zone 2B has a high content of sand, it is usual practice to overbuild the upstream face by up to 0.5 m and to trim the face back to the theoretical section every eight to ten layers using telescopic graders. Because shotcrete and mortar are brittle, the deformations that take place within the rockfill during construction can affect the integrity of the surface protection. Tension cracks can occur at abutment locations where the rockfill tends to settle toward the valley. Within the valley



8-15

locations, the shotcrete can buckle and crack such that pieces of shotcrete slide down the face of the dam. The shotcrete surface may require repair, before placing the slab, if damage is severe. Curb Method of Slope Protection At several recent dams, Ita, Machadinho, Itapebi, Antamina and Mohale, Zone 2B placement and surface protection is taking advantage of a new procedure pioneered during the construction of the Ita CFRD. This method consists on constructing a concrete curb at the upstream face after every layer, and compacting the following layer against the concrete curb. The following description of the method is taken from Materon and Mori, 2000:

“When the extruded curb method is used, the preparation of the slope surface is simplified. An extruding machine is employed using a low cement mix with composition as follows: Cement: 70-75 kg/m3 Aggregate, ¾”: 1173 kg/m3

Sand: 1173 kg/m3 Water: 125 liters The mold of the machine is set to give the same inclination of the upstream face, 1,3H:1V or 1.4H:1V. The construction of the curb follows the following steps:

• Level the compacted layer of Zone 2B to have a horizontal surface for moving the extruding machine.

• Build the extruded curb by using a metallic mold with design height of the layer (usually 0.40 m) and the upstream slope of the face (1.4H:1V).

• Use a dry mix as indicated.

• Control the alignment of the machine by laser equipment mounted on a fixed position on the plinth or by survey crew.

• After one hour, Zone 2B material can be spread. The material may be placed by using an open steel dispenser or unloading the material directly from trucks.

• Level the Zone 2B material with a grader and compact with 4 to 6 passes of the 10-ton vibratory roller. At Antamina CFRD, Peru, the curb is 0.5 m high and Zone 2B material is spread and compacted in two 0.25m high layers.

Benefits of the method are:

• Segregation is reduced.

• Lower losses from material spilling upstream.



8-16

• Immediate protection against erosion and raveling.

• Reduction of construction equipment.

• Safer method of construction avoiding people working on the upstream face.

• High production. Two layers per day are built in dams with a crest length of 500 m.

• Construction equipment is simplified. The extruding machine is low cost equipment.

• Clean work. The face is prepared for rebar placement and construction of the slab reducing excess of concrete.”

The extruded curb is probably the most important improvement to CFRD construction in recent years:

• The curb provides a competent, clean surface for the subsequent operations of form placement, reinforcement placement and slab construction, and

• Better control of the completed alignment of the upstream face substantially reduces the

excess concrete placed in the face slab as compared to the older methods of construction. Figure 8-5 summarizes the construction stages of the curb. The use of the curb method results in several potential difficulties:

• Drainage provisions should be added to the curb to avoid hydrostatic pressure build-up behind the slab and possible uplift during construction and reservoir drawdown.

• Stacked curbs should be capable of withstanding lateral pressures due to compaction.

Compacting the zone 2B face support material in two lifts or constructing the curbs keyed to the lower curb are potential means to solve this difficulty.

• The extruded curb cannot be constructed close to the plinth because the extrusion is

only made at one end of the machine. The curb must be manually completed at this location. As a result, there is a tendency to obtain a higher strength concrete with lower deformability than the extruded curb. In addition, a space has to be left between the curb and the plinth to protect the waterstop and to leave space for placing the sand asphalt mix below it.

• The change in deformability characteristics of materials behind the face creates the

possibility of tension loading, which should be anticipated with appropriate reinforcement details (Marulanda and Pinto, 2000).



8-17

Truck mixerExtruding curbmachine

Extruded faceprotection

PlinthZone 2A

Tractor or grader

Transition, Zone 2B

Vibratory roller

1.4

1

1

8

Typical Extruded Curb

Dam slope

Stage I - Curb Extruded

Stage II - Transition Placing

Stage III - Compaction

Figure 8-5, Curb Construction (from Resende and Materon, 2000)



8-18

Bond Break between the Face Slab and Curb Ita was the first CFRD to use the curb method of face protection. No bond break was used on the surface of the curb to break the bond between the face slab and the curb. It has been suggested that stress transfer between the curb and the face slab may have contributed to the face slab cracking at Ita (Pinto, 2001). Dams constructed subsequent to Ita, such as, Machadinho and Antamina have used a bond break to avoid any possibility of stress transfer between the face slab and the curb. Chapter 6 discusses this issue in more detail.

8.4 Body of Dam (Zones 3A, 3B, and 3C)

The function of the rockfill embankment is to support the concrete face uniformly and with minimum deformation under the water load and its own weight. As with other types of embankment dams, various rockfill materials, soft and hard, weak and strong, have been used successfully as have alluvial sand, gravel, and cobble materials. R. Casinader, 2002, points out that Zone 3A (Zone 2C in Australia) must serve as a transition between Zones 2B and 3B and therefore should be designed in accordance with filter criteria. The magnitude of the fill settlement and deformation is a function of the dam height, the modulus of compressibility of the rockfill, and the shape of the valley (see Chapter 2 for discussion of the influence of these factors). Face slab deflections measured normal to the plane of the face are inversely proportional to the rockfill modulus of compressibility and, for the same modulus, face deflections increase with the square of the dam height. The compacted rockfill long-term deformations take place under conditions of constant stress and are mostly caused by the breakage of the rock particles at the contact points with the consequent rearrangement of particles after each breakage. The magnitude is relatively high following the load application and decreases gradually with time. Contact forces and particle breakage are small in well-graded materials as the void ratio reduces. On the other hand, well-rounded particles are less prone to fracture under load so that the compressibility of a gravel fill will always be significantly less than that of a rockfill of comparable relative density and particle size distribution. The best results are, therefore, obtained by using a maximum density gradation, hard rock, heavy vibratory rollers, optimum layer thickness, and the application of water during compaction (100 to 250 l/m3 of rockfill). Requirements for low compressibility decrease towards the downstream toe. Most of the significant movement as a result of the water load occurs in the upstream two-thirds to three-fourths of the embankment. Therefore, to minimize distortions immediately under the face slab, the most incompressible fill material should be the face support material Zone 2B and the upstream two-thirds or three-fourths of shell, Zones 3A and 3B, which transfer water load to the foundation level. Face cracks developed at Aguamilpa because of the widely different moduli of the gravel fill placed upstream and the rockfill downstream. The downstream shell, Zone 3C, completes the dam section and its behavior in terms of settlement is considered less critical from the point of view of face slab performance. For



8-19

Zone 3C, a greater layer thickness of 1.5 to 2.0 m can be adopted and broader grading limits permitted depending on rock characteristics and dam height. Where good quality rockfill is available, slopes at 1.3 to 1.4H:1.0V have generally been used both upstream and downstream. Somewhat flatter slopes have been selected for weaker rock or when a low strength foundation is present. Slopes should be no steeper than 1.5H:1.0V for sands and gravel materials, steeper slopes cause raveling. Construction of ramps within the embankment is acceptable and provides for a minimum number of access locations to the dam. This is especially important when the material sources are located within the reservoir and points of access across the plinth alignment are necessary. Ramps constructed within the fill should be no steeper than about 15% in any direction; permanent access ramps on the downstream slope should be constructed at slopes no steeper than about 12% (Materon and Mori, 2000). Side slopes of the ramps may be constructed somewhat steeper than those selected for the outer slopes of the dam. All ramps become part of the dam and, therefore, must be constructed to the same specifications for material quality, layer thickness, compaction, and use of water. Care must be taken to avoid loose, high void ratio, rockfill at the outer faces of interior ramps and slopes. Internal cofferdam In addition to the usual zoning of CFRDs, there is often a secondary construction zoning responding to the requirements of river diversion during construction. This “zoning” is used to develop an internal cofferdam within the body of the dam designed to withstand a 500-year flood. Ideally, this internal cofferdam would be constructed upstream, immediately adjacent to the face slab. The lower-permeability zone 2B or a layer of shotcrete on the surface could be used to control the flow through the cofferdam. This scheme is possible only after construction of the plinth and, quite often, because of construction schedule constraints is not a viable option. In this case, it is necessary to construct the internal cofferdam inside the body of the embankment and provide a semi-impervious seepage control barrier on the upstream face of the cofferdam. This barrier should be removed before completing the rockfill to avoid undesirable effects on the drainage characteristics of the rockfill.

8.5 Drainage (Zone 3D)

The CFRD relies on a non-saturated downstream shell for stability. When hard, relatively uniform or well-graded free draining rockfill are used, this requirement is met without difficulty and unexpected high leakage rates through the upstream face will not endanger stability. As has been frequently demonstrated, rockfill and coarse gravel-cobble fills will naturally segregate during placement with the finer less pervious material at the top of the layer and the coarser more pervious material toward the base of the layer. This characteristic provides for a substantially higher horizontal than vertical permeability. Drainage is assured within the entire body of the dam. Often, an underdrain of the coarsest rock (Zone 3D) is placed within the valley section to enhance the overall draining ability of the dam.



8-20

As stated previously, finer and softer rockfill and dirty sands and gravels (7-12% minus No. 200 mesh) with limited permeability can also be used provided suitable zoning is adopted. A free-draining, high-capacity, chimney drain is required. The drain should be placed well back from the upstream face and should have sufficient drainage capacity to ensure that the shell downstream from the drain cannot become saturated under any circumstances. The chimney drain must be connected to an equally free draining zone at the base of the embankment that will discharge freely to tail water (Hacelas, et al, 1985; Cooke, 1960; Vithalani and Beene, 1976; Good, et al, 1985; Amaya and Marulanda, 1985). If the drain is placed immediately under the concrete face, then defects in the face slab, rather than the drainage capacity of the underlying rockfill, is the main factor controlling leakage rates. The appropriate design leakage rates cannot be realistically established since the size and frequency of cracks in the concrete face are difficult to predict. If a semi-pervious zone is introduced between the face slab and the chimney drain, the permeability of the semi-pervious zone imposes an upper limit on leakage rates, even if the concrete face slab is badly cracked. Where required, a layer of filter-transition of appropriate grading (Mackenzie and McDonald, 1980; Hacelas and Ramirez, 1985) can be placed over the abutments to prevent piping of fines into the dam, to allow free drainage of the abutment, and to prevent saturation of the dam body. Using these measures both low strength rocks, weathered low permeability rockfill, and dirty sands and gravels can be put to effective use.

8.6 References

Amaya, F., Marulanda, A., “Golillas Dam-Design, Construction, and Performance”, Concrete Face Rockfill Dams-Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Editors ,ASCE, Detroit, pp. 98-120, 1985.

Casinader, R. J. “Comments on draft ICOLD Bulletin on the CFRD”, 2002. Cooke, J. B., “CFRD-Zone under Face-Designation and Grading” Memo No. 74, 1985. Cooke, J. B., “CFRD-Zone Designation and Zone 2”, Memo No. 97, 1988. Cooke, J. B., “Placement and Grading of CFRD Zone”, Memo No. 117, 1992. Cooke, J. B., Editor, “Symposium on Rockfill Dams”, Transactions, ASCE, Vol 104, 1960. Good, R. J., Bain, D. L. W., Parsons, A. M., “Weak Rock in Two Rockfill Dams”, Concrete

Face Rockfill Dams-Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Editors ,ASCE, Detroit, pp. 40-72, 1985.

Hacelas, J. E., Ramirez, C. A., Regalado, G., “Construction and Performance of Salvajina Dam”,

Concrete Face Rockfill Dams-Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Editors ,ASCE, Detroit, pp. 286-315, 1985.

Hacelas, J. E., Ramirez, C. A., “Salvajina Concrete Face Gravel/Rockfill Dam-Measurement of

some Significant Features”, Proceedings,15th ICOLD Congress, Vol 5, Q56, R8, pp 68-73, 1985



8-21

ICOLD, “Rockfill Dams with Concrete Facing-State of the Art”, International Commission on

Large Dams, Bulletin 70, 1989. ICOLD, "Use of Granular Filters and Drains in Embankment Dams", International Commission

on Large Dams, Bulletin 95, 1994. Marulanda, A., Pinto, N. L. de S., “Recent Experience on Design, Construction, and


Mackenzie, P. R., McDonald, L. A., “Use of Soft Rock in Mangrove Creek Dam”, 20th ANCOLD

General Meeting, 1980. Materon, B., “Transition Material in the Highest CFRDs”, Hydropower & Dams, Issue 6, pp 33-

40, 1998. Materon, B., Mori, R. T., “Construction Features of CFRD Dams”, J. Barry Cooke Volume,

Concrete Face Rockfill Dams, p. 177, Beijing, 2000. Pinto, N. L. de S., “Questions to Ponder on Designing Very High CFRDs”, Hydropower &

Dams, Volume 8, Issue 5, 2001. Sherard, J. L., "Embankment Dam Cracking," chapter in Embankment Dam Engineering -

Casagrande Volume, John Wiley & Sons, New York, 1973. Sherard, J. L., "Sinkholes in Dams of Coarse, Broadly-graded Soils," ICOLD, 13th Congress on

Large Dams, Q.49, R2, New Delhi, 1979. Sherard, J. L., Dunnigan, L. P., and Talbot, J. R., "Basic Properties of Sand and Gravel Filters,"

Journal of Geotechnical Engineering, ASCE, June, 1984a. Sherard, J. L., Dunnigan, L. P., and Talbot, J. R., "Filters for Silts and Clays," Journal of

Geotechnical Engineering, ASCE, June, 1984b. Sherard, J. L., "Hydraulic Fracturing in Embankment Dams," Proceedings, Symposium on

Seepage and Leakage from Dams and Impoundments, ASCE, May, 1985. Sherard, J. L., Dunnigan, L. P., "Filters and Leakage Control in Embankment Dams, Symposium

on Seepage and Leakage from Dams and Impoundments, ASCE, May, 1985. Sherard, J. L., Dunnigan, L. P., "Critical Filters for Impervious Soils, Journal of Geotechnical

Engineering, ASCE, July, 1989.



8-22

Sobrinho, J. A., Sardinha, A. E., Albertoni, S. C., Dijkstra, H. H., “Development Aspects of CFRD in Brazil”, J. Barry Cooke Volume, Concrete Face Rockfill Dams, ICOLD, 20th Congress, Beijing, China, September, 2000.

US Department of the Army, Corps of Engineers, "Earth and Rock-Fill Dams - General Design

and Construction Considerations," EM-1110-2-2300, July, 1994. US Department of the Army, Corps of Engineers, "Engineering and Design - Seepage Analysis

and Control for Dams," EM 1110-2-1901 September, 1986. US Department of Agriculture, Soil Conservation Service, "Soil Mechanics Note No. 1," Guide

for Determining the Gradation of Sand and Gravel Filters, January, 1986. US Department of the Interior, Bureau of Reclamation, "Design Standards No. 13 - Embankment

Dams," Chapter 5 - Protective Filters, May, 1987. Vithalani, J., Beene, R. R., “The Use of Soft Rock for R. D. Bailey Dam”, Proceedings, 12th

ICOLD Congress, Vol 1, Q44, R15, pp 321-325, 1976.



9-1

Chapter 9

INSTRUMENTATION

9.1 Introduction Dams are expected to safely withstand all loading conditions for the design life of the project and beyond. Any sudden or unplanned release of stored water can result in loss of life and property. Potential loss of life, property damage, and the public welfare require a means to evaluate the performance and safety of a dam during construction, during reservoir filling and during project operation. Reasons for installing instrumentation in dams and their foundations include:

• Diagnostic, including o Verifying design assumptions, o Verifying suitability of new construction techniques, o Understanding the specific nature of an adverse event, and o Verifying continued satisfactory performance.

• Predictive reasons include the ability to make informed and valid predictions of the future behavior of the dam based upon the collected data.

• Legal reasons include availability of valid instrumented data for use in evaluating damage

claims arising from dam construction or project operation. • Research, including

o Using available instrumentation and performance data to improve future design features and concepts,

o Developing advances in construction techniques, and o Assisting in a better understanding of failure mechanisms.

A well-constructed CFRD, using compacted rockfill or gravel fill, on a stable foundation is recognized as a fundamentally safe structure. The rate of leakage through some CFRDs exceeded the rate estimated by the designers and/or the rate acceptable to the owners, however, the fundamental safety of the dam was not in question. Instrumentation installed in CFRDs is oriented towards:

• Confirming the expected behavior,

• Identifying potential problem areas,

• Diagnosing problems when they do occur, and

• Promoting improvements to the design features and details of future CFRDs.



9-2

9.2 Limitations

The design of a CFRD at any given site depends on a thorough understanding of foundation conditions and the materials available for use in the body of the dam. Past performance of CFRDs and lessons learned from the performance history at other sites with similar conditions are important elements that contribute to the successful design, construction, and operation of a CFRD. During this evolutionary process, improvements have been made to the techniques available to instrument and monitor the dam. Monitoring of dam behavior using instrumentation provides knowledge of why dams behave the way they do, but monitoring alone does not provide complete understandings. Regular visual inspections (daily, weekly, and/or monthly depending on owner requirements) and evaluations by qualified observers add to the understanding of the performance of the dam. But, there are limitations to what can be instrumented, measured, and observed. It is not possible to place instruments at all locations that later may become critical. Measurements may be taken on an irregular schedule or not at all. Data may be recorded but not evaluated. In some instances, an overwhelming amount of data is collected such that important measurements are overlooked. In time, instruments fail and are not replaced. The instrumentation array, the frequency of readings, the methods used to record, plot and evaluate data, and the need to replace or add instruments should be reviewed in detail every five years. This review should also include a detailed visual inspection of the dam, foundations, and abutments, an evaluation of maintenance and operation, and an analysis of the overall dam and reservoir performance with respect to fundamental safety of the dam.

9.3 Instrumentation Systems The quantity, type and location of instruments depend on design and construction concerns, experience, and common sense; there are no specific guidelines. Generally, the following factors govern the design of the instrumentation system:

• Purpose or need for the instrument,

• Reliability, short term and long term,

• Low maintenance requirements,

• Compatibility with construction,

• Low cost and ease of installation,

• Simplicity,

• Ruggedness. Considering the above factors, an adequate and cost effective instrumentation installation at a new dam will approximate one percent or less of the total construction cost of the dam. Parameters that are commonly monitored and instrument types are listed in Table 9-1.



9-3

Table 9-1

Instruments and Measurements

Property Measured

Measurement Location Typical Instruments

Alignment Crest, slope or other location of interest

Surface monument, Total station, Laser, GPS,

Geodimeter

Deformation or Internal Movement

All points of interest within the dam, foundation, and

abutments

Strain gage, Inclinometer, Settlement cell, Electro-level,

Extensometers

Opening or Crack

Joints of concrete surface Joint meter, Crack meter

Water Pressure

Within the dam, foundation, and abutments Piezometer, Observation well

Rate of Leakage Flow Within the galleries, toe of the dam and any other location of

interest

Weir, flume, flow meter or calibrated container

Quality of Leakage

Any location of interest Turbidity meter

Earthquake Response Dam crest, toe of dam and abutments

Peak acceleration recorder, Strong motion accelerometer,

Microseismic Station Instruments in common use today include:

• Piezometers, mainly the open standpipe and the vibrating-wire piezometer, to measure water pressure at a specific location, generally within the foundation,

• Weirs to measure the rate of leakage through the dam and its foundation,

• Inclinometers, electro-levels, joints meters, settlement cells, bench marks and extensometers to measure deformation, settlement and movement.

Several of these instrument types are described below.



9-4

Piezometers Piezometers are used to monitor the groundwater level and pore water pressure within the dam embankment and/or its foundation. In a CFRD, piezometers are typically installed in the abutments and in the foundation, and not normally within the body of the embankment unless non free-draining materials, such as rockfill or gravel fill with substantial amounts of sand and silt size particles are used. Weirs A weir, flume or other flow-measuring device provides immediate information regarding the performance of the dam. Weirs are placed in strategic locations to measure leakage through the dam and through the abutments and foundation. Overall performance of the dam with respect to leakage can be measured by means of a weir at the downstream toe of the dam. Automated sensing of weir levels and remote read-out of data is encouraged in situations, where monitoring of leakage is critical. Settlement cells Settlement cells, both hydraulic and electric, are used to monitor the settlements that take place within the embankment during construction, reservoir filling, and project operation. Evaluation of settlement data during construction is useful when comparing the performance of the dam to other projects with similar materials. Face deformation during reservoir filling can be estimated using empirical relationships based on analyses of settlement data (see Chapter 2). Electro-levels In addition to the inclinometer, the electro-level is currently being used to monitor the deformation of the face slab during construction, during reservoir filling and during project operation. In several recent dams, the electro-level has replaced the inclinometer for monitoring the face slab deformation. The electro-level consists of a glass capsule partially filled with an electrolytic fluid, commercially known as gravity sensing electrolytic potentiometers. Three or four electrodes penetrate the capsule and are used to measure electric resistance through the fluid. Angular rotations of the electro-levels are monitored as change in the electrical resistance between the electrodes forming a half Wheatstone bridge as shown in Figure 9-1. When the unit is tilted, the electrolytic fluid moves due to gravity, increasing the electrical resistance to one electrode and decreasing the resistance to the other. The relation between rotation and output voltage is obtained by means of a calibration procedure. Individual readings for each electro-level are plotted against distance along the plane of the face slab. Using the measured readings, a polynomial curve is obtained by a curve fitting procedure. The resulting polynomial curve is integrated to obtain a continuous deflection curve. The electro-level has the following advantages:



9-5

• The instrument can be installed easily,

• Data collection is rapid, and

• The instrument can be installed on any steepness of slope, Significantly, the electro-level can be installed and read as soon as the concrete slab is poured. This allows early collection and evaluation of face deformation during construction. A typical installation is shown in Figure 9-3.

5 volts AC input across 1 and 3 / Signal output 2 and 4

Power supply

Voltmeter

AmplifierSimulated E-L

1

2

3

2

3

4

1

1 12 22 233

AC A

mp

32 mm

Figure 9-1 Electro-level schematic layout (Wu, et al, 2000)

Joint Meters Both mechanical and electrical joint meters are available to monitor the joint opening of the concrete slabs. In CFRDs, commonly, electrical joint meters are used. One-dimensional joint meters are used to monitor the joint opening between the concrete face slabs across vertical joints, although two-dimensional joint meters are occasionally used to monitor the lateral and shear movement of the joints. Three-dimensional joint meters are normally used in the perimeter joints to monitor the joint opening in the perpendicular, parallel and tangential directions. Accelerometers There are two types of accelerometers available, peak accelerometer and strong motion accelerometer. The peak accelerometer is used to monitor only the peak response while the strong motion type is used to continuously record the seismic response. The strong motion accelerometer is used in areas of high seismicity and is operated by solar or electric power. Depending on the sensitivity of the accelerometers, strong motion accelerometers can be used to



9-6

monitor low seismic activity, such as that triggered by the reservoir impoundment. They are also equipped with self-contained recording capability. In areas of low seismicity, installing a simple low-cost peak acceleration recorder is sufficient.

1

1

5

1 2

3

5

4

3

A

A

ø40

101.5

6.356.35

6.35

16

13432

120

63.5

95

10

6.35

12345

Brass cylinderWatertight glandBolts holding instrument to concrete slabClamping barSeparate cover and bolts holding it to concrete

Dimensions in mm

Figure 9-2. Electro-level mounting bolted to the Concrete Slab (Penman, 2000)

9.4 Case Histories Tianshengqiao 1 Tianshengqiao 1 (TSQ1), in China, was completed in 1999. At a height of 178 m, TSQ1 is the tallest CFRD in Asia. The rockfill embankment was constructed in seven stages; the concrete face slab was constructed in three stages. The reservoir was impounded simultaneously with dam construction. The dam has a crest width of 12 m, a 5 m high upstream parapet wall, and a cross section typical of other CFRDs. Because of its height and staged construction, TSQ1 was extensively monitored during construction, reservoir filling and project operation. A total of 620 instruments were installed, the type and quantity of instruments are summarized in Table 9.2. The instrument array at the maximum section of the dam is shown in Figure 9-3. During the first two years of operation, a relatively small failure rate of 5.3% was experienced. Settlement Cells. Hydraulic settlement cells were installed at four levels within the embankment to monitor settlement during construction and reservoir filling. Horizontal Extensometer. Invar wire extensometers were installed within the embankment to monitor horizontal deformation. These instruments were installed at the same levels as the settlement cells.



9-7

Table 9-2

Tianshengqiao 1 – Instrumentation Array

Location

Instrument Type

Quantity

Settlement Cell 50 Horizontal Extensometer 31 Total Pressure Cell 28 Single Joint Meter 27 Piezometer 34 Seepage Measuring Weir 3

Rockfill Embankment

Standpipe Water Level Meter 19 Electro-level 64 3-D Joint Meter 36 Single Joint Meter 26 Strain Meter 84 No-Stress Strain Meter 15 Steel Bar Stress Meter 76 Thermometer 27

Concrete Face

Stainless Steel Pins (joint movement)

33

Crest and Slope Surface Monuments 67

Figure 9-3.

TSQ 1 Construction Sequence and Instrumentation at Maximum Section (Wu, et al, 2000)



9-8

Total Pressure Cells. Total pressure cells, in eight groups, were installed at the maximum cross section to monitor the internal stresses within the embankment. The cells were oriented such that the stresses in both vertical and horizontal (normal to the dam axis) could be measured. In the transition zone beneath the concrete face, pressure cells were installed to monitor stresses in the vertical and horizontal (normal to the dam axis) direction and normal and parallel to the upstream slope. Pressure cells were also installed at the contact between the face slab and the Zone 2B beneath the slab. (Total pressure cells are not in common use in many CFRDs and embankment dams in general. In many cases, the data obtained is found to be unreliable.) Electro-levels. Electro-levels were installed at a spacing of about 10 to 15m at the maximum section in the valley and at two abutment sections. The instruments were installed within about seven days after placing the concrete slab. Cables were laid in a trench about 5 cm deep constructed during the slip forming of the face slab. The cables were then routed to the instrument house located on the dam crest. After initial readings were taken and checked, electro-levels were enclosed in a 200 mm x 200 mm x 200 mm concrete box. Single Joint Meters. In the abutments where the vertical face slab joints are expected to open in tension zones, electrical single joint meters were installed to monitor the joint opening. 3-D Joint Meters. Electrical 3-D joint meters were installed along the perimeter joints to monitor the joint movement. The joint meters were oriented to monitor joint opening (movement normal to joint), settlement (movement normal to the concrete face), and shear (movement parallel to joint). Each meter consisted of two gages with a measuring range of 200 mm to measure opening and settlement at the joint, and a third gage with a measuring range of 100 mm to measure shearing movement. Surface Monuments. Monuments were installed at the crest and side slopes to monitor the surface settlement of the embankment. One line of surface monuments was installed on the crest and side slope for each phase of the concrete slab. Seepage Measuring Weir. Seepage measuring weirs were installed at the downstream toe to measure the total seepage through the dam and foundation. Aguamilpa Dam Aguamilpa Dam, in Mexico, currently holds the distinction of the highest operating CFRD in the world at a maximum height of 186 m. The embankment upstream consists of compacted sand and gravel while the embankment downstream consists of compacted rockfill. The dam has a crest width of 12 m and a 5 m high parapet wall. The main focus of the instrumentation was to monitor the embankment deformation, face slab deformation, joint opening, leakage and seismic response. Embankment intrumentation is located at three cross sections, at the maximum cross section in the valley, and one on each abutment. A total of 676 instruments were installed; a summary of the location, type, and quantity are listed in Table 9-3.



9-9

Table 9-3

Aguamilpa CFRD List of Instruments

Location

Instrument Type

Quantity

Remarks

Hydraulic Settlement Cell 82 Inclinometer 6 Horizontal Extensometer 36 Total Pressure Cell 78 Pneumatic Piezometer 14 Seepage Measuring Weir 15 Located in the gallery and at the

downstream toe

Rockfill Embankment

Standpipe Piezometer 27 Located in the abutments and toe Inclinometer 4 On top of concrete face slab 3-D Joint Meter-Electric 19 Perimeter joint 2-D Joint meter-Electric 1 Perimeter joint Single Joint Meter-Electric 35 Perimeter joint

Concrete Face

Mechanical Joint Meter 45 Located at vertical joints on face slab and parapet wall

Crest and Slope

Surface Monuments 301 161 temporary monuments to monitor construction movement, and 140 permanent monuments

Crest and Abutment

Accelerometer 13 2 on the crest, 5 on each abutment, one in the free field

9.5 References ASCE Task Committee on Instrumentation and Dam Monitoring Performance, “Guidelines for

Instrumentation and Measurements for Monitoring Dam Performance”, ASCE American Society of Civil Engineers, Reston, Virginia, 2000.

Bartholomew, C. L., Murray, B. C., and Goins, D. L., Embankment Dam Instrumentation

Manual, A Water Resources Technical Publication, United States Department of the Interior (Bureau of Reclamation), January 1987.

Gonzalez-Valencia, F. and Mena-Sandoval, E., “Aguamilpa Dam Behaviour”, Seventeenth

Annual USCOLD Lecture Series, Non-Soil Water Barrier for Embankment Dams, United States Society on Dams, pp. 133-147, San Diego, California, April 1997.

Hacelas, J. E., Ramirez, C. A. and Regalado, G., “Construction and Performance of Salvajina

Dam”, Concrete Face Rockfill Dams-Design, Construction and Performance, J. B. Cooke and J. L. Sherard, Editors, ASCE, Detroit, October, 1985, pp. 286-315.



9-10

Macedo-Gomez, G., Castro-Abonce, J. and Montanez-Cartaxo, L., “Behavior of Aguamilpa

Dam”, J. Barry Cooke Volume, Concrete Face Rockfill Dams, Beijing, 2000, pp 117-151. Penman, A, and Filho, P. R., “Instrumentation for CFRD Dams”, J. Barry Cooke Volume,

Concrete Face Rockfill Dams, Beijing, 2000. Wu, G. Y., Freitas, M. S. Jr., Araya, J. A. M., Huang, Z. Y. and Mori, R. T., “Tianshengqiao-1

CFRD – Monitoring & Performance – Lessons & New Trends for Future CFRDs (China)”, CFRD 2000, Proceedings, International Symposium on Concrete Faced Rockfill Dams, 18 September 2000, Beijing, China, pp 573-585.



10-1

Chapter 10

PERFORMANCE OF CFRDS This chapter summarizes performance of the CFRD in four tables:

• Moduli of Deformation, Vertical, Ev, and Perpendicular to Concrete Face, Et • Perimeter Joint Movement • Post-Construction Crest Settlement, and • Leakage and Remedial Treatment.

Each table presents the data collected and the source of the information. The full reference is listed at the end of the Chapter. The tables are presented at the end of the Chapter. Hunter, et al, 2003, evaluated the performance of CFRDs. Data are presented that include settlement of the crest and face slab, displacement of joints, cracking, and leakage. The authors provide a framework for assessing:

• Likelihood of initiation of a concentrated leak, • Likelihood of continuation of a concentrated leak, • Likelihood of progression to form a pipe, and • Likelihood of a breach forming through the dam.

Appendix A of the above document presents case study data, figures, and references and provides an overview of the design, construction and performance of a number of CFRDs. The reader is encouraged to obtain this useful reference document.

10.1 Moduli of Deformation Table 10-1 summarizes internal settlement data expressed as the vertical modulus of deformation, Ev, obtained during construction of the CFRD. The table also presents displacement data of the concrete face expressed as the transverse modulus of deformation, measured perpendicular to the concrete face, Et, collected during the first filling of the reservoir. Generally, in each case, maximum values of settlement and concrete face displacement are presented. The use of maximum settlement and displacement data results in minimum values of the moduli. The ratio of the Et to Ev is also presented in the table. The data are arranged by height of dam with the highest dam listed first. Hunter and Fell, 2002, evaluated the deformation behavior of rockfill. Their evaluation includes the following:

• Use of rockfill in CFRDs, • Literature review of rockfill deformation, • Analysis of deformation behavior of the CFRD during construction and during first

filling,



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• Analysis of deformation behavior of the CFRD during reservoir operation including post-construction settlement and internal settlement, and

• Recommended guidelines for deformation prediction during construction, during first filling, and post-construction.

Case-history data on a large number of CFRDs are also presented. The reader is encouraged to obtain this useful reference document.

10.2 Perimeter Joint Movement Table 10-2 presents perimeter joint movement data. The data are arranged by height of dam with the highest dam listed first.

10.3 Post-Construction Crest Settlement The post-construction settlement of the crest with time is presented in Table 10-3. The number of years over which data have been collected, the settlement, height of dam and the settlement expressed as a percentage of the height are given. The data are arranged by height of dam with the highest dam listed first. Clements, 1984, studied post-construction settlement of 18 membrane-face dumped rockfill dams and 9 membrane-face compacted rockfill dams. The dumped rockfill dams ranged in height from 28 to 110 m; the compacted rockfill dams ranged in height from 15 to 110 m. Clements evaluated the settlement data during initial impounding and after 10 years of service. Best-fit analysis, resulting in the following relationship, was used to predict the measured settlement. s = a Hb Where: s = post-construction settlement, meters H = height of the dam, meters a and b = constants depending on type of dam and time of measurement Clements suggested the following values for the constants a and b:

Post-Construction Settlement-Height Relationship Membrane-Face Rockfill Dams

Dumped Rockfill Compacted Rockfill

Constant Initial Impounding 10 years service Initial

Impounding 10 years service

a 1.8 X 10-3 9 X 10-3 2 X 10-4 1.4 X 10-6 b 1.2 0.9 1.1 2.6



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For a dam 100 m tall, the following estimates are obtained using Clements relationships: Dumped rockfill: Initial impounding 0.45 m 10 years service 0.57 m Compacted rockfill: Initial impounding 0.03 m 10 years service 0.22 m All modern CFRDs are constructed with compacted rockfill or compacted alluvial sand and gravel.

10.4 Leakage and Remedial Treatment Leakage and remedial treatment are summarized in Table 10-4. Dams with the largest leakage rates are listed first. Previously, it was not common practice to estimate the seepage through the foundation or the concrete face, however, with the use of soft rockfill or dirty gravels as embankment materials it is becoming increasingly important to estimate this seepage and use the estimate as a basis for sizing the internal drainage system. Seepage through the foundation can be estimated following the usual concepts of flow in porous media, or more complex methods that include the effect of discontinuities in the rock mass, and the effect of the grout curtain (Giesecke et al. 1992). The flow through the cracks and joints in the slab is difficult to estimate, and often it is preferable to resort to case histories, however there have been several attempts to provide a theoretical basis to the calculations, and these methods may be useful to provide additional support to the estimate (Casinader and Rome 1988). A discussion of the techniques to estimate leakage through cracks and joints in the face slab is presented in Chapter 2. Leakage is a key parameter concerning the overall performance of the CFRD. Large leakage rates are an indication that opening has occurred to the perimeter and/or face joints and/or that the concrete face has cracked to some extent. Seepage through the foundation may also be a contributing factor to large leakage rates. The fundamental design concept of the CFRD is that the several embankment zones of the dam including the face support material, filters, transitions, under drainage and the body of the dam remain stable even if extremely large leakage rates were to occur. The ability of rockfill to accept and pass large flows is well known in the literature. Thus, if the embankment zones and the foundation treatment have been designed and constructed appropriately, the large leakage rates are not an indication that safety is a problem, but rather that remedial treatment may be needed to reduce the leakage.



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Hydro Tasmania CFRD Experience Damien Kenneally, 2003, Table 10-5, reports leakage rates at CFRDs owned by Hydro Tasmania.

Table 10-5

Hydro Tasmania CFRDs, data current as of April 2003

Dam Year Completed Height (m) Type of

Dam Current Base Leakage, l/s Rockfill Type Remedial

Action

Anthony Dam 1993 42 CFRD 3 Conglomerate and Sandstone No

Bastyan Dam 1983 75 CFRD 3 Rhyolite No

Cethana Dam 1971 110 CFRD 5 Quartzite No

Crotty Dam 1991 82 CFRD 20 Glacial Gravels No

Mackenzie Dam 1972 14 BFRF 1 Dolerite No

Mackintosh Dam 1980 75 CFRD 4 Greywacke No

Murchison Dam 1982 93 CFRD 6 Rhyolite No

Newton Dam 1990 37 CFRD 4 Tuff, Porphyry, Sandstone and

Siltstone No

Paloona Dam 1973 43 CFRD 0.5 Argillaceous Chert No

Reece Dam 1987 122 CFRD Not measured Dolerite No

Scotts Peak Dam 1973 43 BFRF 3 Argillite Yes

Serpentine Dam 1971 38 CFRD Not measured Quartzite No

Tullabardine Dam 1981 25 CFRD 2 Greywacke No

White Spur Dam 1989 44 CFRD 4 Tuff No

Wilmot Dam 1970 34 CFRD 0.5 Greywacke No

Legend:

CFRD Concrete Faced Rockfill Dam

BFRD Bitumen Faced Rockfill Dam

In general, excellent performance is reported. Only one dam required remedial treatment. Most CFRDs that have performed well are not widely discussed in the literature.



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Experience in China Dr. Jia Jinsheng, 2003, reports the current leakage rates at several CFRDs in China:

• Shisanling upper reservoir, pumped storage hydro o Concrete lined area 175,000 m2, o Head 75m, o Leakage 5 l/s.

• Guangzhou upper reservoir, pumped storage hydro o Head 68 m o Leakage less than 1 l/s

• Tianhuangping lower reservoir, pumped storage hydro o Head 97 m o Maximum leakage 55 l/s, repaired in 1999 by emptying the reservoir, leakage

reduced to less than 5 l/s • Xikou upper reservoir, pumped storage hydro

o Head 37 m o Maximum leakage 7.7 l/s

• Qinshan CFRD with corrugated rubber waterstop over the top of the perimeter joint o Head 122 m o Leakage 4 l/s

• Tianshengqiao, see following discussion o Head 182 m o Leakage as of 2003, 132 l/s

• Chenping o Head 75 m o Leakage approximately 70 l/s

• Wan-anxi o Head 94 m o Maximum leakage 25 l/s

• Guanmenshan o Head 59 m o Leakage 5 l/s

• Longxi o Head 59 m o Leakage 3 l/s

Two problem dams were reported:

• Gouhou, head 70 m, failed as a result of the opening of the joint between the face slab and the parapet wall following deformation of the zoned gravel embankment. Joint detailing and construction of the dam were poor.

• Zhushuqiao, head 78 m, leakage tested at 2500 l/s, repaired in 2000 and 2001 after emptying the reservoir. This case history is described later, p 10-13.



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CFRDs in China have, in general, performed well and, as a result, are often the selected dam type. The following are under construction in 2003 using the corrugated rubber waterstop:

• Shuibuya, head 233 m • Hongjiadu, head 180 m • Jilintai, head 152 m • Zipingpu, head 156 m • Yinzidu, head 139 m • Bajiaohe, head 115 m

Several case histories of dams that included remedial treatment to reduce seepage are summarized below: Turimiquire (Cooke, 2000) The 115-m tall Turimiquire Dam in Venezuela was completed in 1980. The design was typical of CFRDs constructed during that time period. The outer slopes of the dam are 1.4H:1V upstream and 1.5H:1V downstream, a conservative design for the excellent limestone rockfill. The Zone 2 face support material consists of minus 150 mm crusher run rockfill, a material that will segregate into lenses and streaks of fine and coarse material. The dam was well zoned and well constructed. A large capacity limestone rockfill underdrain is located at the base of the dam downstream of the dam centerline. The reservoir did not begin filling until 1988 because of delay in the completion of the water transfer tunnel. Nearly complete filling of the reservoir occurred during the period, 1988 to 1991; maximum leakage during this period was 300 l/s. In 1994, leakage increased to 5,400 l/s at a rate of about 500 l/s per day over a 10-day period. Tremie placement of silty fine sand was immediately undertaken and the reservoir was drawn down. During the summer of 1995 a second repair by tremie placement of silty fine sand was undertaken; leakage reduced to about 2000 l/s with the reservoir about 5 m from full. During the rising reservoir in 1996, leakage increased to 3000 l/s. A third repair was undertaken; leakage reduced to 1600 l/s with a full reservoir. Because of water supply requirements, leakage at rates up to 3000 l/s is acceptable. In mid-1999, with full reservoir, leakage increased to over 6000 l/s. Leakage reduced to less than 4000 l/s as a result of tremie placement of silty fine sand and gravel, the fourth repair. A repair that included the placement of 7,850 m2 of a PVC geomembrane was implemented in the latter half of 2000. Leakage reduced from 6000 l/s to somewhat over 600 l/s. Leakage was detected using a hydrophone and establishing decibel contours. The leak was concentrated at a location at and above the perimeter joint in an area where the abutment slope is steepest. Divers and a TV camera made detail inspections of the area. A remotely operated vehicle (ROV) was also used in subsequent inspections. The map of the cracked area gives the appearance of an incident that started at the perimeter joint and progressed to a curved major crack above the perimeter joint. The mechanism of failure is visualized to be:

• An initial leak at the perimeter joint, cause unknown, • Erosion and some of the Zone 2 material into the adjacent Zone 3,



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• Nearby cracking as a result of loss of face slab support, and • Progression of cracking as leakage increased and additional fine-grained material is

removed. One m by 2 m block-outs had been made in the concrete face in order to install piezometers subsequent to the construction of the concrete face. Defects in the later construction of the support for the block-outs and the backfilling of the block-outs are suspected as contributing to the leakage problem. Aguamilpa The reservoir began filling in mid-1993. Leakage peaked at about 63 l/s, then reduced to only a few liters per second. In late 1994, leakage increased to 260 l/s, reservoir level at elevation 219, 16 meters below the top of the parapet wall. Flows decreased to below 50 l/s during the summer of 1995 and 1996 with reservoir levels slightly below elevation 200. In 1997, several horizontal and diagonal cracks were detected in the concrete face between elevations 198 and 202. A study of the inclinometer data showed irregularities at several elevations. Diver inspection of the concrete face discovered a horizontal crack at elevation 180 crossing about 10 slabs, 150 m, with maximum opening of 15 mm. The crack was partially sealed with silty sediment; at some locations leakage was evident. The sudden increase in leakage in 1994 is thought to have been the result of cracks opening as the reservoir was raised to nearly full pool. The reduction is attributed to the sealing of the cracks with sediment and with some reduction of the reservoir level following the rainy season. The owners engineering staff believe that during the rainy season each year, the cracks open because the pool level increases. As sediment-laden water passes through the cracks, the cracks seal and seepage is reduced. The structure of the sediment is weak and, subsequently, during the next rainy season the cracks re-open and leakage again increases. Peak flows in 1998 and 1999 were 214 and 173 l/s, respectively. Minimum flows in 1998 and 1999 were <50 and <100 l/s, respectively. A plan has been developed to seal the crack at elevation 180. Recent inspections of the crack have indicated a lengthening on the order of 40 m; total length is now about 190 meters. Generally, the performance of Aguamilpa has been satisfactory. Face slab cracking was attributed to differential settlements caused by the use of dissimilar embankment materials. At Aguamilpa, low compressibility alluvial material was placed within the upstream shell of the dam while relatively high compressible rockfill was placed in the downstream shell. Xingo During fill placement, cracks in the surface of Zone 2B were observed, close to the left abutment. Cracks had an average width of 20 mm but some were as wide as 56 mm and were essentially vertical. Offsets of the order of 15 mm were reported. Initially the cracks were sealed on the surface with mastic and fill placement resumed. New openings within the same cracks occurred as well as new cracks at higher elevations in the same zone. Prior to the



10-8

placement of the face slab, cracks were filled with sand; the surface was re-graded, then compacted with a vibratory roller.

Settlements and deformations at Xingo continued within the rockfill zones after reservoir filling. Normal behavior was reported during the first 1.5 years with leakage on the order of 110 l/s. Subsequently, the rate of settlement of several instruments increased significantly over a period of about six weeks, then returned to similar rates recorded prior to the increase. Leakage increased to rates ranging from 180 to 200 l/s. Diver inspections indicated major cracks in the same areas where cracks had occurred in Zone 2B during construction. At one location, an 8-m long crack, 15 mm wide, was detected and an offset of about 300 mm was observed between two slabs. The on-going settlement, face cracking, and the increase in leakage were closely related (Sousa, 1999). Leakage penetrated the dam fill reaching layers of less pervious material where rockfill with higher fines content was placed. It is believed that the increased rates of settlement were caused by wetting and saturation as a result of the increased leakage in this area. The increased settlement caused cracks to open further. Most probably, cracks in the Zone 2B material opened again allowing increased leakage. Re-opening of cracks also explains why the complete sealing after dumping of dirty sand was not obtained. The increase in the rate of leakage was attributed to the opening of the joints and cracks in the concrete slabs of the left abutment (openings of 36 mm were observed). Hair-line cracks were detected in the face slab before the filling of the reservoir but they were not treated since they were superficial. Cracks appeared on the left abutment during the construction period and appear to have been produced by the topography of the rocky foundation in the left abutment, strongly inclined in the downstream direction. Remedial treatments were carried out because of the slow stabilization of displacements in the left abutment and to preserve the integrity of the material supporting the face slab. The observed rates of leakage are considered acceptable, Eigenheer, et al, 1999. Ita Reservoir filling began in late February 2000; a full reservoir was reached in late April 2000, two months later. Leakage increased from 160 l/s in late February to 1700 l/s in mid-May, a period of about 2 ½ months. Inspections of the face slab using divers and a remotely operated vehicle (ROV) revealed a series of horizontal and sub-horizontal cracks in 15 panels, 10 to 15 meters above the perimeter joint. The cracks occurred toward the right abutment under a reservoir head of 65 to 85 meters. Cracks were found to be open as much as 7 mm. Dumping of clay and sand were successful in reducing the leakage from 1700 l/s to 380 l/s. The underlying cause of the face cracks is not known. Analyses of data collected from the instrumentation system indicate no abnormal behavior. Additional foundation grouting was also underway at the same time as the remedial clay-sand dumping. The grout curtain was deepened in the area between the dam and the spillway gate structure to treat pervious interbeds between basalt flows. The extent to which the abutment is a



10-9

source of leakage is not known and the effect of the additional foundation grouting in reducing leakage is not known. Modern CFRDs have emphasized the need for filter protection at the perimeter joint. At that location, the zone 2A is well compacted as is the adjacent zone 2B. The result is a dense, high modulus material located within three to six meters of the perimeter joint. At distances away from the joint the face slab is supported by a less dense material, thus creating the possibility of bending stresses and face slab cracking on the order of eight to ten meters above the perimeter joint. Some engineers have suggested that this condition may have contributed to the face slab cracking at Ita. Ita was the first CFRD to use the curb method for face protection. No bond break material was used on the surface of the curb to break the bond between the face slab and the curb. Some engineers have suggested that stress transfer between the curb and the face slab may have contributed to the face slab cracking at Ita. Chapter 8 includes a description of the curb method for surface protection. Golillas The following description of leakage at Golillas is taken from Amaya and Marulanda, (2000): “At Golillas the situation was more complex, because leakage took place through these joints, but also through the plinth foundation. Since the problem was not completely solved, and leakage is still occurring, the development is summarized: • During the first filling of the reservoir, a rapid erosion of the clayey fills in the main joints in

some sectors of the foundation was evident, producing total seepage surpassing 500 l/s, with a tendency to be higher. This condition forced the emptying of the reservoir, when it was at 50% of its height.

• After repair works at elevation 2915 m in the right abutment, at the contact between the

plinth and the foundation, reservoir filling was completed, almost to its maximum level (El. 2995 m). Still important leakage was registered, but more controlled, on the order of 1080 l/s.

• The operators of the project lowered the reservoir to elevation 2965 m. This allowed

treatment of the area close to the abutments. Upstream of the plinth, above this elevation, loose material was removed, cleaned and the main joints were filled and finally the surface was reinforced with shotcrete. The next filling of the reservoir only registered a total seepage of 650 l/s, half of what was measured before. This is attributed to two main facts: with the superficial treatment, the seepage path for the foundation was doubled (the plinth was incremented with the reinforcing of the slope) and the fine materials that fell in the perimeter joint during cleaning.

• During the next 15 years of operation, a period during which the dam has not experienced

any more important deformation, seepage reduced in a natural way. At the maximum



10-10

reservoir level seepage was around 270 l/s. About mid 1999, after the reservoir remained at its maximum level (El. 2997.5 m) during 10 months, a time much longer than usual, seepage increased suddenly by more than 200 l/s to approximately 470 l/s. This could have been generated by the partial washing of the material deposited in the perimeter joint.”

The leakage did not affect the stability of the dam, however, a pumping system to return the water to the reservoir was implemented. An analysis indicates that this measure is economical because the water that is returned to the reservoir can generate more energy than is required for pumping. “It is clear that the design of the triple seal used at Golillas was not adequate. The intermediate PVC seal shears and the mastic did not penetrate the upper seal when movement is essentially vertical. Some mastic can lose plasticity with time or low temperature, as occurred at Golillas.” Minase The Minase Dam was completed in 1964 by the Ministry of Construction, Japan. The following is a summary of pertinent data: • The 66.5-m-high dam was constructed in the period 1958-1963.

• The foundation consists of fine-grained sedimentary rocks, shale, tuff, and mudstone.

• Rockfill slopes, downstream 1.4H:1V between 5 m wide berms every 20 m (1.65H:1V overall average slope) and 1.35H:1V upstream. The angle of repose of quarry rock was 1.3H:1V and shaking table results indicated that a 1.4H:1V slope was stable when subjected to 0.2g acceleration.

• The rockfill forming the body of the dam was liparite. The rockfill was placed in lifts (thickness not presented in the reference) and compacted by sluicing with a volume of water about four times the fill volume. The void ratio of the sluiced rockfill was 0.41.

• The concrete face was placed on rockfill described as “packed large rock”.

• The concrete face was placed in slabs mostly measuring 10 m by 10 m. The area of the steel reinforcement was 0.5% of the area of the concrete section.

First filling of the reservoir resulted in about 10 cm of crest settlement and 10 cm of horizontal displacement at the crest. The maximum values of settlement and horizontal displacement of the concrete face at about mid-height were 33 cm and 28 cm respectively. Leakage after reservoir filling, as measured by a weir at the downstream toe, measured 220 l/s at the highest water level. This leakage was not considered to be excessive. However, upon inspection of the face, the horizontal joints at about mid-height of the dam and the perimeter joint at the left abutment were repaired. As a result, leakage reduced to about 100 l/s. In June, 1964, Minase Dam was shaken by the Niigata Earthquake (M 7.5, 147 km epicentral distance from the dam, 75 cm/s2 estimated peak ground acceleration at the dam). As a result of this earthquake, the crest settled about 15 cm and displaced horizontally about 10 cm. The



10-11

earthquake temporarily increased leakage from about 100 l/s to somewhat over 200 l/s. Within a few days, leakage returned to pre-earthquake levels. Long term settlement over the period, 1963 to 1975, added another 15 cm for a total of 40 cm over 12 years. Total horizontal crest displacement was about 30 cm over the period, 1963 to 1975. Leakage gradually increased over the years as a result of the long-term settlement. By mid-1978, 15 years after the first reservoir filling in 1963, the leakage had increased to 400 l/s at full pool. Repair of the concrete face, consisting of the placement of “gravel asphaltic mastics” over the entire face, was undertaken during the period 1980 to 1983. Leakage reduced to essentially zero. In 1983, the M 7.7 Mid-Japan Sea Earthquake occurred at an epicentral distance from the dam of 223 km. The measured peak ground acceleration at the dam was 34 cm/s2, the measured crest acceleration was 76 cm/s2. The predominant frequency at the foundation was about one second and the duration of the motion was 80 seconds. Post-earthquake leakage was nil. Khao Laem (Vajiralongkorn, renamed in 2001) This multipurpose project in central west Thailand faced extremely difficult foundation conditions (Watakeekul and Coles, 1985). The dam is founded on interbedded shale, sandstone, siltstone both calcareous and non-calcareous, locally interbedded with limestone, and karstic limestone. The strata have undergone severe faulting. Partially infilled cavities up to several meters across were encountered at numerous locations. Solution features were found to depths of 200 m below the base of the dam. Extensive foundation treatment was performed along the alignment of the plinth (see Chapter 3, Foundation Treatment and Watakeekul and Coles, 1985). For the shell foundation, overburden excavation in the upstream one quarter of the base width was approximately to rock (Cooke, 2001). Under the remainder of the shell foundation, the weathered decalcified sandstone and the limestone blocks floating in a clay matrix were left in place. The following description of performance is taken from Cooke, 2001. The project has been operating successfully since 1984, when the reservoir was filled. The foundation settled at the axis of the dam 0.5 to 1.4 m during construction. Post-construction crest settlement after 13 years is 15 cm, 0.16% of the height of the dam. During the period, 1984 to 1994, seven leakage incidents were treated. In each case, leakage increased from about 30 l/s to about 100 l/s or to a maximum of 200 l/s. Cracks in the face were treated with sand; rope was used in several of the wider cracks, measuring up to 5 mm. During the wet season of 1994, the reservoir filled and leakage rose from about 140 l/s to 980 l/s. A 20-cm depressed cracked area was located by diver and by a remotely operated underwater vehicle (ROV). Dumping gravel and sand over the cracked area reduced leakage to 340 l/s. Sand with fines was not used. The cracked area was drilled and grouted, resulting in leakage reduction to 25 l/s. The cracked area is located near the slope between two rockfill placement stages and where two stages of the concrete face connected. In addition, at this location, the foundation rock slopes steeply downward. It is believed that the initial cause of the cracks is the



10-12

differing support to the face slab and the collapse as a result of progressive erosion within the Zone 2B. In November 2000, 16 years after first filling of the reservoir, leakage suddenly increased from a stable 100 l/s to 900 l/s. Within two weeks, leakage had increased to 2,200 l/s. The leakage source was at mid-height of the dam where the dam is 90 m tall. At that location, the plinth required a 50-m-deep cutoff wall of overlapping concrete piles to penetrate large cavities in the limestone foundation. Downstream, under the rockfill embankment, a thickness of about 40 m of limestone blocks floating in a clay matrix (“plum pudding”) was left in place. The damaged face slab measured 7 m across and had collapsed to a depth of 30 cm. The collapse was centered on a vertical joint (at Khao Laem, the horizontal reinforcing steel is continuous through the joints). Shearing and offset of the face slab had occurred at the edges of the roughly circular damaged area. The face support zone, 2B, is 8-inch crusher run limestone with 60% minus one inch, 20% minus the #4 sieve, and 2-5% passing the #200 sieve. The material was coarse and susceptible to segregation. The contractor was allowed to place an upstream face layer of 0.4 m of fine material because of the difficulty in handling the coarse Zone 2B. Repair was achieved by filling the large gap at the perimeter of the damaged area, first with gravel, followed by hydraulic mortar and sand. Leakage was reduced to 50 l/s. Subsequent to this treatment, the slab support material was grouted on 2.5 m centers within an area, 12.5 m square. Two potential causes of the failure have been suggested: • A leak in the waterstop that over time resulted in removal of fines and face support until

collapse occurred. • A sinkhole located in the downstream limestone blocks/clay matrix foundation that reflected

to the face slab by rockfill loosening and collapse. Strawberry Dam Larson, 2003, describes remedial treatment at Strawberry Dam, a 44-meter-high CFRD constructed in 1916 in the high Sierra Mountains of California. Leakage through the dam is primarily through the nine expansion joints in the face slab. Leakage is measured at a weir located at the toe of the dam. From 1969 through 1986, leakage averaged about 170 l/s. In 1987, leakage increased to 370 l/s and continued to increase progressively until it reached a maximum of about 600 l/s in 1998. Temporary remedial repairs that included polyurethane caulking in the expansion joints reduced the leakage to about 550 l/s. Extensive repairs, undertaken starting in 2001, consisted of the following:

• Removal of freeze-thaw damaged concrete at each expansion joint. Because of time constraints and more extensive concrete removal than originally anticipated, the joint repairs were rescheduled, with portions of some joints not repaired.



10-13

• Placement of concrete in each repaired joint, using forms to retain the concrete, and • Placement of a geomembrane over each repaired joint.

Although the repair did not include the full length of all joints, the leakage was reduced by 85%, which exceeded the acceptance criteria. Zhushuqiao Dam (Li, et al, 2004)

Zhushuqiao Dam, an 84-m-high CFRD, is located in Hunan Province, China. The upstream slope is 1.4H:1V and the downstream slope is 1.7H:1V. Limestone was used for the cushion zone I (Zone 2B), the transition zone II (Zone 3A), and the main rockfill zone III (Zone 3B). Except for a zone III underdrain, weathered slate, rockfill zones IV and V (Zones 3C and 3D) was used downstream of the dam centerline. Construction of the rockfill zones began in 1988; construction of the second stage of the concrete face was completed mid-year 1992. At normal maximum water level 165, the freeboard equals 6 meters. The parapet wall height is 4 m. The design included the placement of the concrete face on a portion of the left and right abutments. At the intersection of the dam and abutments, a dramatic change occurred in the deformation characteristics of the foundation (rockfill as compared to the natural abutment rock) of the concrete face. Instrumentation included settlement cells within the body of the dam, joint meters to measure movement at key locations, and movement observations of the concrete face. Joint meters were located on the vertical joints in the concrete face at the junction of the dam and abutments. The reservoir was filled to about elevation 161, four meters below the normal maximum water level, shortly after the completion of the second stage concrete face in mid-1992. The reservoir was filled to full reservoir level, elevation 165, in June 1993. Leakage was on the order of 40 l/s in 1993. At full pool in 1994, leakage had increased to 970 l/s. Leakage continued to increase until 1999 when leakage at full reservoir reached 2500 l/s. Maximum settlement within the body of the dam reached 1100 mm in 1999. Maximum measured joint movement at perimeter joints and at joints at the junction between the dam and abutments was 11.5 mm settlement, 11.2 mm opening, and 26.7 mm shear. Monitoring the settlements within the dam and movements at the perimeter joints indicated that the deflection of the concrete slab was large, that the cushion zone was separating from the concrete slab, and that damage at the perimeter joints at the steep abutments was occurring. As a result of increased leakage, the reservoir was emptied in 1999. The analysis of the leakage mechanism indicated the following development:

• The water seal of the vertical joints and the perimeter joints failed, • Leakage through the joints caused erosion of the cushion zone into the underlying

rockfill, • Concrete face separation from the cushion zone caused cracking in the slab,



10-14

• Increased leakage through the slab caused further cracking, loss of support and further increased leakage.

Major causes of the progressively-increasing leakage included:

• Opening, settling, and shearing of the vertical perimeter joints between the slabs on rockfill and the slabs on the abutments caused by the completely dissimilar deformation characteristics of the dam and the abutments, and

• Gradations of the materials used for the cushion zone and the transition zone were incompatible. This allowed piping of the cushion zone into the transition and rockfill zones and resulted in loss of support of the concrete slab.

First stage treatment, carried out prior to the flood season 2000, consisted of:

• Grouting the voids between the concrete slab and the cushion zone with mortar, • Placement of a new concrete face slab, 200 mm thick (400 mm in badly damaged

locations), and • Crack and joint repairs.

Second stage treatment, carried out in 2001, consisted of:

• Continuation of grouting the voids within the cushion zone with a mix consisting of cement, coal fly ash, and bentonite, and

• Placing an impervious geomembrane, clay, and random material over the face of the dam. Conclusion Clearly, leakage has been a problem at some CFRDs, but many examples are found in the literature and in the record of owners and operators where leakage has been quite modest. As an example, the recently completed first stage Antamina CFRD in Peru, 140 m high, has a leakage rate of less than one liter per second. High leakage rates, even if safety is not jeopardized, are embarrassing to the engineer, the constructor and the owner and are to be avoided wherever possible.



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Table 10-1

Moduli of Deformation, Vertical, Ev, and Perpendicular to Concrete Face, Et

Dam Country Year

completed Height,

m Rock type Ev, MPa(2)

Et, MPa(3) Et/Ev

Data Source(1)

Aguamilpa Mexico 1993 187 Gravel

Gravel/rockfill Rockfill

260 130 47

680 -- --

2.6 -- --

2

Tianshengqiao China 1999 178 Limestone and mudstone 45 120(5) 2.7 7 and 8

Foz do Areia Brazil 1980 160 Basalt 47 110 2.3 3 Salvajina Colombia 1984 148 Gravel 390 630 1.6 1

Alto Anchicaya Colombia 1974 140 Hornfels-Diorite 145 440 3.0 1

Segredo Brazil 1993 140 Basalt 60 170 2.8 3 Xingo Brazil 1994 140 Granite 32 125 3.9 3

Khao Laem Thailand 1984 130 Limestone 45 380 8.4 1 Golillas Colombia 1984 125 Gravel 210 310 1.5 1 Shiroro Nigeria 1984 125 Granite 76 -- -- 1

Ita Brazil 2000 125 Basalt 60 104 1.7 3

Machadinho Brazil Under

construction (2000)

125 Basalt 30 -- -- 3

Reece Australia 1986 122 Dolerite 160 200 1.3 1 Cethana Australia 1971 110 Quartzite 135 300 2.2 1

Itapebi Brazil Under

construction (2000)

106 Granite-gneiss 40 -- -- 3

Kotmale Sri Lanka 1984 97 Charnokite 50 -- -- 1 Xibeikou China 1991 95 Dolomite 100(4) 130 1.3 5

Murchison Australia 1982 89 Rhyolite 225 590 2.6 1 Crotty Australia 1991 83 Gravel 500 400 0.8 10

Mackintosh Australia 1981 75 Graywacke 40 100 2.5 1 Bastyan Australia 1983 75 Graywacke 160 280 1.7 1

Chengbing China 1989 75 Lava tuff 78 110 1.5 6 Minase Japan 1963 67 Liparite ? 31(6) -- 9

Pichi-Picun-Leufu Argentina 1999 40 Gravel 360 360 1.0 4

Antamina Peru 2001 140 Hornfels 100 105 1.1 11 El Pescador Colombia 2002 43 Diabase 60 -- -- 11

Notes, Table 10-1: (1) 1 Pinto and Marquez, 1998

2 Macedo-Gomez, et al, 2000 3 Sobrinho, et al, 2000 4 Marques, Machado, et al, 1999 5 Peng, 2000



10-16

6 Wu, Hongyi, 2000 7 Wu, G.Y. et al, 2000 8 Shi, J, et al, 2000 9 Matsumoto, N., et al, 1985 10 Fitzpatrick et al, 1985, and Hydro Tasmania dam monitoring record 11 Marulanda, Alberto, 2002, personal correspondence

(2) The vertical modulus of deformation, Ev, is calculated based on the measured settlement of the rockfill during construction using the equation: Ev = stress/strain = overlying rockfill load, in MPa, above the settlement gage divided by the ratio of the measured settlement in meters to the thickness of rockfill below the settlement gage in meters. (3) The modulus of deformation of the rockfill supporting the concrete face, Et, in MPa is calculated using the following equation: Et = 0.003 H2/D, (see Pinto and Marquez, 1998) where H equals the height of the dam in meters, and D equals the measured face displacement in meters at about the mid-height of the slab under the load of a full reservoir. (4) At the end of eight years of observations at Xibeikou Dam, the internal settlement at gage 11 at about mid-height of the dam measured 650 mm, indicating a vertical modulus of deformation, Ev, of about 50 MPa. Vertical deformation of the face slab at about mid-height of the dam after eight years of impoundment increased from about 100 mm to about 250 mm. (5) The transverse modulus of deformation at Tianshengqiao was calculated based on the equation indicated in note (3) above and using a value of 80 cm of concrete face deflection measured at about mid-height of the dam and a dam height of 178 m. Settlements and face deflections were affected by the staging of the dam construction and the reservoir filling. See Wu, G. Y. et al, 2000, for an explanation of the sequencing of the dam construction. (6) For the Minase Dam, the transverse modulus of deformation was calculated based on the equation indicated in note (3) above and using a value of 43 cm (33 cm settlement and 28 cm horizontal displacement) of concrete face deflection as measured during first filling and a dam height of 67m. Note that the rockfill was compacted by sluicing the rockfill, see the Minase case history description below.



10-17

Table 10-2 Perimeter Joint Movement

Perimeter Joint Movement, mm Dam Country Year

completed Height,

m Rock type O* S* T*

Data Source**

Aguamilpa Mexico 1993 187 Gravel 19 16 5 2

Tianshengqiao China 1999 178 Limestone and mudstone 16 23 7 6

Foz do Areia Brazil 1980 160 Basalt 23 55 25 1 Salvajina Colombia 1984 148 Gravel 9 19 15 1


Diorite 125 106 15 1

Xingo Brazil 1994 140 Granite 30 34 -- 2 Golillas Colombia 1984 130 Gravel -- 160 -- 10

Khao Laem Thailand 1984 130 Limestone 5 8 -- 1

Cirata Indonesia 1988 126 Breccia-Andesite 10 5 8 7

Shiroro Nigeria 1984 125 Granite 30 >50 21 1 Reece Australia 1986 122 Dolerite 7 70 -- 1

Cethana Australia 1971 110 Quartzite 11 -- 7 1 Kotmale Sri Lanka 1984 97 Charnokite 2 20 5 1 Xibeikou China 1991 95 Dolomite 14 25 5 4

Murchison Australia 1982 89 Rhyolite 12 10 7 1 Sugarloaf Australia 1982 85 Sandstone 9 19 24 1

Crotty Australia 1991 83 Gravel 2 27 -- 9 Mackintosh Australia 1981 75 Graywacke 5 20 3 1

Bastyan Australia 1983 75 Graywacke 5 21 -- 1 Chengbing China 1989 75 Lava tuff 13 28 20 5

Pichi-Picun-Leufu Argentina 1999 40 Gravel 2 12 1 3

Serpentine Australia 1972 39 Quartzite 1.8 5.3 -- 1,8

Paloona Australia 1971 38 Argillaceous Chert 0.5 5.5 -- 1,8

Tullabardine Australia 1982 26 Greywacke -- 0.7 0.3 1,8 * O = Opening, normal to joint, S = Settlement, normal to concrete face, T = Shear, parallel

to joint ** 1 ICOLD, Bulletin 70, 1989

2 Pinto and Marquez, 1998 3 Marques, Machado, et al, 1999 4 Peng, 2000 5 Wu, Hongyi, 2000 6 Wu, G.Y. et al, 2000 7 Kashiwayanagi et al, 2000 8 Fitzpatrick, et al, 1985 9 Knoop, B.P. 2002 (personal communication) 10 Amaya and Marulanda, 1985



10-18

Table 10-3

Post-Construction Crest Settlement

Dam Rock type Height, m Period Years Settlement,

mm % of

height Data

Source* Aguamilpa Gravel 187 1993-2000 7 340 0.18 3

Tianshengqiao Limestone and mudstone 178 1999-2000 1.5 1060 0.60 6

Areia Basalt 160 1980-2000 20 210 0.13 4 Xingo Granite 150 1993-1997 4 490 0.33 1

Segredo Basalt 145 1992-2000 8 160 0.11 4

Alto Anchicaya Hornfels-diorite 140 1974-1994 20 170 0.12 1

Ita Basalt 125 1999-2000 2 450 0.36 4 Golillas Gravel 125 1978-1984 6 57 0.04 8

Khao Laem Limestone 115 1984-1998 14 150 0.16 1 Turimiquire Limestone 115 1978-1995 17 270 0.23 1, 2

Kenney Basalt, 40’

lifts, sloping core dam

100 1952-1998 46 950 0.95 1

R. D. Bailey Sandstone and shale 96 1980-1998 18 420 0.44 1

Sugarloaf Weathered siltstone 85 1984-1997 13 40 0.04 1

Crotty Gravel 83 1991-2000 9 56 0.07 9 Chengbing Lava tuff 75 1989-1999 10 100 0.13 5

Minase Liparite 67 1963-1975 12 400 0.60 7 Cabin Creek Gneiss 64 1966-1995 29 110 0.22

Kangaroo Creek Weak schist 60 1969-1998 29 180 0.30 1

Taum Sauk Limestone, dumped 36 1963-1998 35 450 1.50 1

* 1 Cooke, Memo 161, 1998 2 Cooke, Memo 130, 2000

3 Macedo-Gomez, et al, 2000 4 Sobrinho, et al, 2000 5 Wu, Hongyi, 2000 6 Wu, G.Y. et al, 2000 and 4th Summary on Instrumentation Data 7 Matsumoto, N., et al, 1985 8 Amaya and Marulanda, 1985 9 Fitzpatrick et al, 1985, and Hydro Tasmania dam monitoring record



10-19

Table 10-4

Leakage and Remedial Treatment

Dam Country Year completed

Height, m Rock type

Initial Leakage,

l/s

Remedial Treatment

Leakage after

Repair, l/s

Data Source*

Turimiquire Venezuela 1987 115 Limestone 6000 Yes, see text See text 2


Diorite 1800 Yes 180 1

Shiroro Nigeria 1984 125 Granite 1800 Yes 100 1 Ita Brazil 2000 125 Basalt 1700 Yes 380 3

Golillas Colombia 1984 125 Gravel 1080 Yes 650 1 Segredo Brazil 1993 140 Basalt 400 Yes 70 3 Minase Japan 1963 67 Liparite 400 Yes Nil 7

Aguamilpa Mexico 1993 187 Gravel 260 Yes 100 1 Foz do Areia Brazil 1980 160 Basalt 236 Yes 60 1

Xingo Brazil 1994 140 Granite 160 200

Yes Yes

100 150 3

Tianshengqiao China 1999 178 Limestone

and mudstone

100 No -- 6

Salvajina Colombia 1984 148 Gravel 60 No -- 1 Chengbing China 1989 75 Lava tuff 60 No -- 5

Khao Laem Thailand 1984 130 Limestone 53 Yes, see text -- 1, 8

Crotty Australia 1991 83 Gravel 38 No -- 9 Mackintosh Australia 1981 75 Graywacke 14 No -- 1 Pichi-Picun-

Leufu Argentina 1999 40 Gravel 13 No -- 4

Cethana Australia 1971 110 Quartzite 7 No -- 1 Murchison Australia 1982 89 Rhyolite 7 No -- 1

Bastyan Australia 1983 75 Graywacke 2 No -- 1

* 1 Pinto and Marquez, 1998 2 Cooke, Memo 130, 2000 3 Sobrinho, et al, 2000 4 Marques, Machado, et al, 1999 5 Wu, Hongyi, 2000 6 Wu, G.Y. et al, 2000 7 Matsumoto, N., et al, 1985 8 Cooke, Memo 178, 2001 9 Fitzpatrick et al, 1985, and Hydro Tasmania dam monitoring record



10-20

10.5 References

Amaya, F., Marulanda, A., “Colombian Experience in the Design and Construction of Concrete

Face Rockfill Dams”, J. Barry Cooke Volume, Concrete Face Rockfill Dams, ICOLD, 20th Congress, Beijing, China, September, 2000.

Amaya, F., Marulanda, A., “Golillas Dam – Design, Construction and Performance”,

Proceedings, Concrete Face Rockfill Dams – Design, Construction, and Performance, Cooke, J. B. and Sherard, J. L. editors, ASCE, 1985.



Clements, R. P., “Post-Construction Deformation of Rockfill Dams”, Journal of Geotechnical

Engineering, Vol. 110, No. 7, pp 821-840, July 1984 Cooke, J. B., “Memo No. 178, Khao Laem Dam Performance, 1984-2000”, June 2001. Cooke, J. B., “Memo No. 130, Turimiquire Dam 1980-1995 Performance”, October 1995,

Revised, May, 2000. Cooke, J. B., “Memo No. 161, CFRD Time/Settlement Curves”, August 1998. Eigenheer, L. P., De Queiros, T., Barbosa de Souza, R. J., “Xingo Concrete Face Rockfill Dam”,

Proceedings, Second Symposium on Concrete Face Rockfill Dams, Brazilian Committee on Dams, Florianopolis, Brazil, October, 1999.

Fitzpatrick, M. D., Liggins, T. B., Lack, L. J., Knoop, B. P., “Instrumentation and Performance

of Cethana Dam”, Proceedings, 11th Congress on Large Dams, Q42, R9, Madrid, 1973. Fitzpatrick, M. D., Liggins, T. B., Barnett, R. H. W., “Ten Years Surveillance of Cethana Dam”,

Proceedings, 14th Congress on Large Dams, Q52, R51, Rio de Janeiro, 1982. Fitzpatrick, M. D., Cole, B. A., Kinstler, F. L., and Knoop, B. P., “Design of Concrete-faced

Rockfill Dams”, Concrete Face Rockfill Dams, Design, Construction, and Performance, J. B. Cooke and J. L. Sherard, Eds., American Society of Civil Engineers, Detroit, October 1985.

Giesecke J., Rommel M., Soyeaux R. 1991, “Seepage flow under dams with jointed rock

foundation”, Proceedings, 17th Congress on Large Dams, Vienna, 1991.



10-21

Gonzalez-Valencia, F., Mena-Sandoval, E., “Aguamilpa Dam Behavior”, Proceedings, 17th Annual USCOLD Lecture Series, Non-Soil Water Barriers for Embankment Dams, San Diego, CA, April, 1997.

Good, R. J., “Kangaroo Creek Dam, Use of a Weak Schist as Rockfill for a Concrete Faced

Rockfill Dam”, Proceedings, 12th Congress on Large Dams, Q44, R33, Mexico City, 1976. Hacelas, J. E., Ramirez, C. A., “Salvajina: A Concrete-Faced Dam on a Difficult Foundation”,

Water Power & Dam Construction, p 18, June, 1986. Hunter, G., Fell, R., “The Deformation Behaviour of Rockfill”, UNICIV Report No. 405, The

University of New South Wales, Sydney, Australia, January, 2002. Hunter, G., Glastonbury, J., Ang, D., Fell, R., “The Perfomance of Concrete Face Rockfill

Dams”, UNICIV Report No. 413, The University of New South Wales, Sydney, Australia, January, 2003.

Jinsheng, J., Private correspondence, 2003. Kashiwayanagi, M., Koizumi, S., Ishimura, Y., and Kakiage, H., “A Fundamental Study on the

Face Slab Joint Behavior of the CFRD”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, International Committee on Large Dams, China, September 2000.

Kenneally, D., Private correspondence, 2003 Knoops, B. P., Personal Communication, April 2002. Larson, E., “Plugging Leaks with Concrete and Plastic”, Hydro Review, p. 52, May, 2003. Li, Nenghui, Ma, Guicang, Guo, Dihuan, He, Guolian, “Large Leakage and its Treatment of

Zhushuqiao Dam”, Proceedings, Workshop on Dam Safety Problems and Solutions-Sharing Experience, International Committee on Large Dams, Seoul, Korea, May, 2004.

Louis, C., “A Study of Groundwater Flow in Jointed Rock and its Influence on the Stability of

Rock Masses”, Rock Mechanics Progress Report No. 10, Imperial College, London, September, 1969.

Macedo-Gomez, G., “Concrete Face Behavior of Aguamilpa Dam”, Proceedings, Second

Symposium on Concrete Face Rockfill Dams, Brazilian Committee on Dams, Florianopolis, Brazil, October, 1999.

Macedo-Gomez, G., Castro-Abonce, J., Montanez-Cartaxo, L., “Behavior of Aguamilpa Dam”,

J. Barry Cooke Volume, Concrete Face Rockfill Dams, ICOLD, 20th Congress, Beijing, China, September, 2000.



10-22

Marques Filho, P. L., Machado, B. P., Calcina, A. M., Materon, B., Pierini, A., “Pichi-Picun-Leufu, A CFRD of Compacted Gravel”, Proceedings, Second Symposium on Concrete Face Rockfill Dams, Brazilian Committee on Dams, Florianopolis, Brazil, October, 1999.

Marulanda, A., Amaya, F., Millan, M., “Antamina Tailings Dam”, Proceedings, International

Symposium on Concrete Faced Rockfill Dams, Beijing, China, September, 2000. Marulanda, A., Pinto, N. L. de S., “Recent Experience on Design, Construction, and


Materon, B., “Alto Anchicaya Dam – Ten Years Performance”, Proceedings, Concrete Face

Rockfill Dams – Design, Construction, and Performance, Cooke, J. B. and Sherard, J. L. editors, ASCE, 1985.

Matsumoto, N., Takahashi, M., Sato, F., “Repairing the Concrete Facing of Minase Rockfill

Dam” Proceedings,15th International Congress on Large Dams, Q59, R13, Lusanne, 1985. Mori, Rui, T., “Deformations and Cracks in Concrete Face Rockfill Dams”, Proceedings, Second

Symposium on Concrete Face Rockfill Dams, Brazilian Committee on Dams, Florianopolis, Brazil, October, 1999.

Peng, Z., “Analysis of Deformation of Xibeikou CFRD in Eight Years of Operation”,

Proceedings, International Symposium on Concrete Faced Rockfill Dams, Beijing, China, September, 2000.

Penman, A. D. M., “The Behaviour of Concrete Faced Rockfill Dams”, Hydropower & Dams, p

85, Issue 2, 1998. Pinto, N. L. de S., Materon, B., Marques Filho, P. L., “Design and Performance of Foz do Areia

Concrete Membrane as Related to Basalt Properties”, Proceedings, 14th Congress on Large Dams, Q55, R51, Rio de Janeiro, 1982.

Pinto, N. L., Marques, P. L., “Estimating the Maximum Face Deflection in CFRDs”,

Hydropower and Dams, Issue 6, 1998, p. 28. Regalado, G., Materon, B., Ortega, J. W., Vargas, J. “Alto Anchicaya Concrete Face Rockfill

Dam – Behavior of the Concrete Face Membrane”, Proceedings, 14th Congress on Large Dams, Q55, R30, Rio de Janeiro, 1982.

Shi, J., Zhu, B., Liang, C., “Characteristic and Experience of the Design, Construction and

Performance of TSQ-1 Concrete Face Rockfill Dam”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, Beijing, China, September, 2000.



10-23

Sobrinho, J. A., Sardinha, A. E., Albertoni, S. C., Dijkstra, H. H., “Development Aspects of CFRD in Brazil”, J. Barry Cooke Volume, Concrete Face Rockfill Dams, ICOLD, 20th Congress, Beijing, China, September, 2000.

Thongsire, T., Suttiwong, P., “Safety Surveillance and Remedial Works for Khao Laem Dam”,

Proceedings, International Symposium on High Earth-Rockfill Dams, Beijing, 1993. Watakeekul, S. and Coles, A. J., “Cutoff Treatment Method in Karstic Limestone-Khao Laem

Dam”, Proceedings, 15th ICOLD Congress on Large Dams, Q. 58, R. 2, Luasanne, 1985, pp. 17-38.

Wu, G. Y., Freitas, M. S. Jr., Araya, J. A. M., Huang, Z. Y., Mori, R. T., “Tianshengqiao-1

CFRD – Monitoring and Performance – Lessons and New Trends for Future CFRDs (China)”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, Beijing, China, September, 2000.

Wu, Hongyi., Wu, J., Wang, S., Wu, Q., Cao, K., “Ten Years Surveillance of Chengbing

Concrete Face Rockfill Dam”, Proceedings, International Symposium on Concrete Faced Rockfill Dams, Beijing, China, September, 2000.

Zuyu, C., “Breaching of the Gouhou Concrete Face Sand and Gravel Dam”, Proceedings,

International Symposium on High Earth-Rockfill Dams, Beijing, 1993.



–11-1

Chapter 11

APPURTENANT STRUCTURES The design of the dam includes its correlation and connection with adjacent and appurtenant structures. Sometimes a layout responding to particular site conditions requires special connections between the concrete slab or the plinth and the spillway or the low level outlet. These connections are usually designed case by case but some general rules and practices can be discussed.

11.1 Low Level Outlet Low-level outlets are required at most projects. They are used for controlled filling of the reservoir, emergency drawdown, minimum releases or other functions. Low-level outlets crossing an earth core embankment dam have been discouraged because of the creation of potential seepage paths at the contact between the core and the outlet. Low-level outlets through a CFRD present a new set of issues. An example of the type of treatment is shown in Figure 11-1. Geometry at the outlet becomes complicated by the size and the hydraulic requirements of the outlet. In private correspondence, Casinader suggests placing the intake tower upstream of the plinth as was done for Sugarloaf dam in Australia.

Low level outlet tower

Joint around tower

Existingwaterstop

Spit anchor

Rodflex fiberglassmembrane

Rodimpermmembrane

0 0.25 0.5 meters

Figure 11-1 Connection low level outlet and concrete slab Connection with the Plinth A low-level outlet conduit crossing the plinth needs to be treated as part of the plinth. The base of the conduit can be used as a grout cap without difficulty, as for the rest of the plinth. The



–11-2

conduit, however, complicates the geometry of the perimeter joint and requires special sharp angled joints in the waterstops that can lead to larger joint movements than might be otherwise expected. This in turn could lead to substantial leakage at the joints in contact with the low-level outlet. Face Slab Supporting Filter The filter zones behind the perimeter joint and extending around the conduit are always of fundamental importance, and more so in the area around a connection between a conduit and a plinth, and deserve careful consideration during design and construction. Because of the irregular conduit geometry, proper compaction of the materials adjacent to the conduit becomes difficult. These restrictions can result in locally poor compaction of the perimeter joint filter that could cause movement of the slab and opening of the perimeter joint. Dam Zoning The dam zoning requires modification around the conduit to avoid damage resulting from stresses transferred by the edges of large rockfill. Protective transition zones should surround the conduit

11.2 Connection to Spillway and Intake Walls Location of spillways and intake structures adjacent to the CFRD introduce additional complexity to the design of these structures, and the toe and face slab of the CFRD. Walls adjacent to the concrete face need to be treated as very steep abutments. The details of the design of the plinth, which becomes part of the wall, the perimeter joint and the supporting filter zones, need to consider the particular geometric restraints that are introduced. The height of these walls should be restricted, when possible, to prevent probable rupture of the waterstop as a result of the deformations of the fill, and the tendency of the face slab of pulling away from the steep structure wall or natural abutment. Details of the joint should be similar to the details used in CFRDs in steep canyons, considering past experiences such as Golillas. Moderately high connections have been performed successfully at several projects. Figure 11-2 shows the detail used in Caruachi Dam in Venezuela, where a connection with a 50 m high spillway wall was constructed and is operating successfully. This detail was an evolution of a similar detail used in a lower connection with a spillway in Macagua Dam, also in Venezuela, constructed a few years before.



–11-3

Membrane

Concrete face

Vertical face

Protective capLean concrete

Bituminous filler4mm x 200mm or similar

Waterstop

Concrete face rockfill dam Concrete gravity dam

0 0.2 meters

Figure 11-2 Connection spillway and concrete slab

11.3 Spillways over the Dam

Several successful cases of placing a spillway on the downstream slope of the rockfill have been reported in the literature (Steven et al. 1993, several authors J. Barry Cooke Volume 2000), and more will be designed and constructed as designers gain confidence on the concept. The spillway excavation is one of the largest costs and construction schedule issues associated with construction of CFRDs, and any cost and time-savings are welcome improvements. Including the spillway crest on top of the dam and placing the spillway chute on the downstream face brings important economic advantages to the CFRD. Current layouts have used the spillway on top of the embankment to evacuate flows up to three or four meters of head over an ungated spillway at the crest. The spillway on the embankment is usually considered to provide only additional spilling capacity while the main spillway is often provided in a separate structure. A spillway over the embankment, however, has been used as the only spillway in pumped storage projects where the upper reservoir is a closed basin or presents only a small tributary area. In these cases, the spillway is sized to accommodate the full capacity of the facility in the pumping mode.



–11-4

The principal design concerns to be considered when placing the spillway on top of the CFRD embankment are: Settlement of the Crest The post-construction settlement of the crest of CFRDs has been extensively studied, and the general consensus and evidence is that much of it occurs during construction of the fill. But some vertical and horizontal displacement occurs in response to the filling of the reservoir and long-term settlement and horizontal displacement continues to occur at rates that decrease with time. Chapter 10 summarizes the post-construction crest settlement of a number of CFRDs. A concrete structure at the crest will need to accommodate these movements. This can normally be accomplished using carefully designed joints and good compaction of the selected rockfill placed as foundation during construction. The use of gated spillways on top of the embankment is discouraged because of their sensitivity to movement. Settlement of the Downstream Face The settlement and displacement of the upstream face of CFRDs have been carefully monitored and studied but the behavior of the downstream slope has been less researched. Current design criteria for CFRDs provide rockfill zones in the downstream half of the dam in such a way that the downstream face is formed by lower modulus of deformation materials. This results in larger deformations in response to loading. Spillway placement on the embankment will require a modification of the embankment zoning and compaction requirements to limit deformation. Flow Over the Spillway The flow over the spillway chute generates high dynamic forces. To resist these forces and maintain the stability of the chute slabs, the flow per unit width has usually been restricted to 10 m3/s per meter of chute width, and the slabs are anchored to the fill using steel rebars. Some thought has been given to the use of stepped spillways similar to that used for roller-compacted concrete spillways to avoid difficulties associated with high velocity flow, but experience is limited.

11.4 References BRACOLD (ed.), II Symposium on CFRD dams, Bracold-Engevix-Copel, Florianopolis, Brazil,

October, 1999. Amaya, F., Marulanda, A., “Golillas Dam – Design, Construction and Performance”,

Proceedings, Concrete Face Rockfill Dams – Design, Construction, and Performance, Cooke, J. B. and Sherard, J. L. editors, ASCE, 1985.

He, G., “Technical Study on Crest Overflow of Concrete Faced Rockfill Dams”, Proceedings,

International Symposium on Concrete Faced Rockfill Dams, ICOLD, 20th Congress, Beijing, China, September, 2000.



–11-5

Marulanda, A. Pinto, N. de S. (ed.), J. Barry Cooke Volume, Concrete Face Rockfill Dams,

ICOLD, 20th Congress, Beijing, China, September, 2000. Steven, S. Y. et al, “Design of Crotty Dam Spillway", Proceedings Int. Symposium on High

Earth- Rockfill Dams, Chinese Committee on Large Dams, 1993.



1

5.- GUIDE No. 4 - DESIGN FLOOD

As mentioned earlier, the 1996 Technical Regulations are less restrictive in nature and

oriented in a different direction from the 1967 Regulations, which are in fact eminently

technical and detailed, specifically for Dam Design, Construction and Operation, and

mandatory in nature. For three decades these regulations were applied for building the largest

number of dams in Spain. The 1996 Regulation constitutes a less restrictive framework-

standard with a different philosophy of setting up concepts and criteria aimed at safety control

and management, a logical development as the number of dams to be built in the future will

be far less than those already built and which, in turn, are now ageing. It is also true that the

public today demand better living standards, taken to mean greater safety.

Outstanding within structural safety is the major role played by hydrological safety.

The 1996 Regulation devotes several chapters to this subject which, in turn, this Guide

attempts to clarify and enlarge upon.

The 1967 Regulations denote two floods purely as a function of their return period -

the Standard Flood where T=50 years and the Design Flood where T=500 years. The 1996

Regulation stipulates that three types of flood should be considered, namely Standard, Design

and Extreme, and consequently Standard Maximum Levels, Design Flood Level and Extreme

Flood Level.

These evaluations take into account the assumable potential risk derived from a

possible dam failure or incorrect operation, to which end dams are classed into three

categories (A, B and C), in accordance with the Civil Defence Planning Directive for Risk of

Flood which appears in the 1996 Regulation. This classification has been defined in the

preceding Guides.

The issue of hydraulic safety must be taken into account for the dams to be built in the

future and for adapting the dams built prior to publication of the Directive.

This Guide No. 4 goes into broad detail in its treatment of the interrelation between

floods and dams and the downstream effects.



2

Broadly speaking, this Guide is arranged into the following sections:

1. Introduction.

The importance given by the 1996 Regulation to hydrological safety, floods and the

capacity of the spillways and outlets.

2. Criteria for evaluating river floods.

3. Methods for estimating floods:

- Rate of flow data

- Historical data

4. Hydrometeorological methods.

5. Recommendations for evaluating the floods to be considered in reservoirs.

Given the content of this Guide and the 1996 Technical Regulation, the criteria of

certain specialists, the treatment given by other countries to this issue and the risk-based

classification of dams, Guide No. 4, "Design Flood", RECOMMENDS that the values to be

taken into account for the Design Flood and the Extreme Flood be those shown in Table 2:

TABLE 2.- DETERMINATION OF DESIGN FLOODS

RETURN PERIODS IN YEARS

DAM CATEGORY DESIGN FLOOD EXTREME FLOOD

A 1000 5000 – 10000 B 500 1000 – 5000 C 100 100 - 500

In Category B and C dams, other values could be justified for extreme floods based on

carrying out economic risk analyses in order to determine the optimum capacity of the water

discharge elements.

The RECOMMENDATION given for large rockfill dams is to select the value

corresponding to the top limit of the return period as the extreme flood.

In dam design and construction, special attention needs to be paid to river diversion,

particularly in rockfill dams. The floods to be considered in designing the diversion should be



3

determined as a function of the assumable risk during dam construction (Art. 11.3).

Generally speaking, the RECOMMENDATION for Category A large dams is that the

acceptable risk is taken to be in the order of magnitude corresponding to the design flood of

each particular dam throughout its useful life.

In Category A concrete dams, the RECOMMENDATION given is that the probability of

exceedance of flow rate levels during the effective construction period is less than 20%, and for

Category B and C dams it is between 20 and 25%. In Category A embankment dams, this

probability will be less than 5%, and in Category B and C dams it will be between 5 and 10%.

In Category A dams, an additional RECOMMENDATION is that these values are

analysed, and modified where applicable, as a function of the results obtained from an

economic risk analysis study taking into account the cost of the diversion works and the cost

of the damage done to the construction site and downstream.

Reservoir Levels

Standard maximum level, design flood level and extreme flood level plus their

respective freeboards are defined in Articles 11-11.3-1 and 13 of the 1996 Technical

Regulation for Dam and Reservoir Safety.

The ANNEX includes the different methods for calculating floods, geared to the

engineers wishing to go into the subject in greater depth.

The 1996 Regulation opts for a probabilistic flood study contemplating historical floods wherever

possible.



Dams and Floods. New Trends in Hydrological Safety of Dams

Berga, L. Chairman of ICOLD Committee on Dams and Floods, Orense 3, 28020 Madrid, Spain

E-mail: [email protected]

ABSTRACT: The floods constitute the most important disaster among the natural hazards, since they represent about 30% of the total number of natural disasters and economic damages, and almost 25% of the fatalities produced by the natural disasters. ICOLD Committee on Dams and Floods has carried out a survey on the social and economic impacts of the floods in the most important countries in large dams, with greater incidence in floods. The paper shows the values of the “mean” number of fatalities per year, the annual economic damages, and several flood impact indicators. Also an updating of the data and envelope curves of the extreme floods in the world are described. Past experience and statistical data demonstrate that the most frequent cause of dam failure is overtopping, which constitutes almost 40% of the failures, having produced the 87% of these failures in embankments dams. So, the hydrological safety is an essential element in dam safety, for which criteria of minimum risk should be adopted in the selection of the design flood. In the paper the continuous and progressive evolution of the basic criteria for the selection of the design flood is described. These criteria have the main aim of increasing the hydrological safety of dams, with the formulation of standards with greater objectivity, quantification and consistency. The current approaches and their advantages and shortcomings are discussed, as well as the new trends and methodologies in the hydrological safety of dams. Finally the works developed by the ICOLD Committee on Dams and Floods are described, the Bulletin 125 of recent publication, in which the" Guidelines for the design flood", and the criteria for the analysis of the hydrological safety of existing dams are analyzed. 3. DAMS AND FLOODS. HYDROLOGICAL SAFETY OF DAMS The dams and the floods have a mutual interrelation. On the one hand the floods suppose a danger for the integrity of the dams and for their safety, and on the other hand the dams and the reservoirs play an important role in flood routing, and are one of the most efficient structural measure to mitigate the damages produced by the floods. (Berga, 2000).

Dams signify an irreplaceable contribution for the economic development and quality of life of the population, and in each country they suppose important economic and social benefits for the water supply, irrigation, hydropower, flood control, navigation, recreational activities and other uses. However, the large dams also represent a hazard, an environmental risk in their effect on the environment and a hazard for the downstream population, due to their potential failure, which is very improbable, but experience shows us that it is not totally impossible. From all that, the great importance of the Dam Safety which constitutes an essential element in the field of Dam Engineering. On the other hand, it must be taken into account that actually there exists a great social demand in activities involving risk imposed on the population, and that the issues referring to the dam safety are related and deal jointly with the environmental concerns.

ICOLD has carried out numerous works and studies on failures and incidents of dams and the last statistical data at world level is of the year 1995, the Bulletin nº 99 of ICOLD on “Dam Failures, Statistical Analysis” (ICOLD,1995). These statistics showed that there have been 176 cases of failures in 30 countries, excluding China, which represent about 1% of the existing dams, with a global incidence and a mean probability of failure of 10-4 per dam and year. Nevertheless, it must be taken


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into account that the failures of large dams have been reduced very significantly during the last decades. So whilst before 1950 the percentage of failures was of 2.2%, in the dams constructed after 1950 this percentage was of 0.5%, in those constructed after 1970 the percentage was 0.3%, and in dams constructed after 1980 the percentage of failures has dropped to 0.2%, which is an evident sign of the achievements reached in the field of dam safety.

The greater part of the failures, an 80%, are embankment dams, and the remaining 20% correspond to concrete dams, the failure of the embankment dams having an incidence 70% greater than the concrete dams. The majority of failures have occurred in dams less than 30 m high with 70% of the failures. Also, it is interesting to point out that the greater part of the failures are produced in “young” dams with a 70% of failures in their first 10 years of life, of which 25% correspond to the first year, which indicates the high grade of incidence and importance of the phase of first filling.

The main causes of dam failure are the following: • In masonry dams the main cause is overtopping (OV), with 34% of the failures, followed by

the internal erosion of the foundation with 29% of the failures. • In concrete dams the main causes of failure are foundation problems, with internal erosion

and insufficient shear strength of the foundation, each accounting for the 21%. The second cause is the OV with 12% of the failures.

• In embankment dams the main cause of failure is OV, with 50% of the failures. Piping represents 15% of the failures, and internal erosion of the foundation 12% of the failures.

In short, the main cause of dam failure is overtopping, which represents 37% of the failures, the 87% of these failures caused by overtopping has been produced in embankment dams. In relation to the failures due to the OV it can be pointed out that although the total incidence of failures has diminished in a very significant manner during the last decades, the percentage of failures due to OV is continuing to maintain almost constant, which indicates the importance that the hydrological safety of the dams continues to have. (Table 5).

Table 5. Dam Failures. OV

DAM FAILURES ( % )

FAILURES DUE TO OV. ( % )

BEFORE 1950 2,2 38 AFTER 1950 0,5 36 AFTER 1970 0,3 43 AFTER 1980 0,2 37 TOTAL 1.0% 37%

From the analysis of the failures, the following general conclusions can be deduced:

• The floods play a very important role in the life of the dams. • In dam safety a carefully attention should be paid to the hydrological safety, for which

criteria of minimum risk must be adopted in the design flood assessing. • The embankment dams are extremely vulnerable to overtopping, including during the

construction. • The spillways and outlet works should be well maintained, in order that they are operative

during the floods events. 4. GUIDELINES FOR THE SELECTION OF THE DESIGN FLOOD

Up to the middle of the decade of the 1970’s, the criteria used for the selection of the Design Flood was of a general type, a criteria which could be nominated as FIRST GENERATION CRITERIA, and were based on empirical and general considerations applicable to any dam and in any situation, without taking into account its size, typology, reservoir volume, nor the downstream hazard. But, it is



clear that dam safety is not only a general concept, but that it is also specific to each dam, and consequently the fundamental philosophy of hydrological safety must be the relationship between the design flood and the downstream hazards, demanding particular attention to the safety of high hazard dams.

The first practical formulations on the Dams Classification were developed in 1974 by the U.S. Army Corps of Engineers in their “Recommended Guidelines for the Safety Inspection of Dams”, in which the dams were classified following two criteria: first, size classification, according to the reservoir capacity and the height of the dam in three categories: small, intermediate and large, and second, according to the downstream potential hazard, evaluating the potential impacts in loss of life and economic losses, in three categories: low, significant and high hazard dams. (Berga,1998).

For this scheme of dam classification stemmed numerous variants and actually there exists a wide variety of formulations for dams classification, based as well as on the downstream hazard, on the dam size, on the dam factor (which is the product of the height of the dam by the volume of the reservoir), on the characteristics of the power plants, on the irrigation area, on the purpose of the regulated water, or in same cases, on general criteria applicable to all dams due to the fact that all could present a high hazard. Nevertheless, in the majority of the cases of the new dam safety regulations, the trend is that the downstream hazard provides the basic and fundamental criteria for the dam classification, which is denominated Dam Hazard Classification (Table 6). (USACOE, 1997).

Table 6. Hazard Potential Classification.

CATEGORY LOW SIGNIFICANT HIGH Direct Loss of Life None expected (due to

rural location with no permanent structures for human habitation)

Uncertain (rural location with few residences and only transient or industrial development)

Certain (one or more extensive residential, commercial or industrial development)

Lifeline Losses No disruption of services-repairs are cosmetic or rapidly repairable damage

Disruption of essential facilities and access

Disruption of critical facilities and access

Property Losses Private agricultural lands, equipment and isolated buildings

Major public and private facilities

Extensive public and private facilities

Environmental Losses Minimal incremental damage

Major mitigation required

Extensive mitigation cost or impossible to mitigate

The current hydrological safety criteria, denominated SECOND GENERATION CRITERIA, are based, in general, on the dam hazard classification, with demands of greater hydrological safety for the dams of greater hazard.

The criteria for the Design Flood are the following: • The principal criterion for the assessing of design flood is the Classification of dams

according to their potential hazard (Dam Hazard Classification). • In general, the classification of dams is established in three categories: High, significant and

low hazard dams. • The potential loss of lives is the main factor for the classification (Table 7).



Table 7. Dam Hazard Classification

DAM HAZARD CATEGORY LOSS OF LIFE ECONOMIC, SOCIAL, ENVIRONMENTAL

POLITICAL IMPACTS HIGH ≥ N EXCESSIVE

SIGNIFICANT 0 - N SIGNIFICANT LOW 0 MINIMAL

The boundary between the high hazard dams and the significant hazard dams is established quantitatively according to the loss of lives, being equal or superior to N. The value of N varying normally between 1 and 10-20 lives.

• Adoption of the maximum safety measures and standards for the high hazard dams. In this case the design flood is the PMF or very long return periods (10,000 years)

• The world trends can be classified in two large groups: - USA, United Kingdom, Australia, and other countries under their technological

influence employ deterministic criteria and methods, the PMF. - Most European countries use probabilistic methods with return periods ranging from

1,000 to 10,000 years, for the high hazard dams. There also exists the possibility of considering two floods on the dams: the design flood and the

safety check flood or the extreme flood. The design flood is the inflow flood to consider for the design of spillways and energy

dissipating structures, with a safety margin provided by the freeboard. The safety check flood is the most extreme flood that the dam could support without failure, but

also with a very low safety factor, which is denominated a “scenario limit” for the floods. In this case, a limited amount of overtopping could be permitted for the concrete dams, but not in the embankment dams.

The formulation existing in numerous countries, and the trends of the new standards and regulations on the selection of design floods could be synthesized in the criteria recommended in the ICOLD Bulletin 125(ICOLD, 2003), (Table 8).

Table 8. Selection of Design Floods

DAM HAZARD CATEGORY

LOSS OF LIFE

ECONOMIC, SOCIAL, ENVIRONMENTAL, POLITICAL IMPACTS

DESIGN FLOOD

SAFETY CHECK FLOOD OR INFLOW DESIGN FLOOD

HIGH >N EXCESIVE %PMF or 1,000 – 5,000

PMF or 5,000 – 10,000

SIGNIFICANT 0-N SIGNIFICANT %PMF or 500-1,000 or ERA (Economic Risk Analysis

%PMF or 1,000 – 5,000 or ERA

LOW 0 MINIMAL 100 100 - 150 Dam hazard classification in three categories: High, significant and low hazard dams, quantitative evaluation of the loss of life, according to N which varies between 1 and 20, qualitative evaluation of the economic, social, environmental and political impacts of the potential failures in excessive, significant and minimal, and selection of the design flood and the safety check flood for each category.

In the high hazard dams, the design flood is a % of the PMF, usually the 50%, or the flood for a return period between 1,000 and 5,000 years, the safety check flood is the PMF, or return periods



between 5,000 and 10,000 years, the higher values being those recommended for the embankment dams.

In the final analysis, each country must determine what is an acceptable level of risk according to its own resources and technical, economic, social, cultural and political criteria, while taking into account the necessity for measures of maximum safety for dams which present a high downstream hazard.

5. NEW TRENDS IN HYDROLOGICAL SAFETY OF DAMS

The practical application of the current criteria has been object of various criticisms and has given rise to different controversies in their application, mainly in their application to existing dams and their accommodation to the high hydrological standards. So, from the analysis of the actual criteria, several problems and considerations have arisen, which are based on the following points:

1. The methodology of hydrological standards approach is very conservative, principally in the selection of the PMF for he high hazard dams, and does not explicitly quantify the risk, putting all its emphasis on the concept of safety.

2. In the dam Hazard Classification, dam with a wide range of potential consequences are classified as high hazard dams. For example, the selection of the design flood is the same if the number of potential loss of life is 10, 1,000, 10,000 or 100,000 lives. So, the relation between the categories of dams and the consequences of their potential failure is stepped and discontinuous, when with a more rational approach it should be more direct and continuous.

3. A very important problem is the practical implantation of the new standards to the existing dam, which supposes substantial economic investment in the accommodation of the existing dams, since the general philosophy is that existing dams should comply with the new dam safety criteria.

4. On the other hand, in the last years a great and important technical activity has been developed in the field of dam safety with the celebration of many Symposiums and Congresses in which dam safety has played a very outstanding part, and numerous countries are revising and applying new laws, regulations and guidelines on dam safety.

Equally, ICOLD has been promoting and stimulating the improvement of dam safety, and its Committee on Dam Safety has published a new Bulletin on the concepts and methodologies of the risk analysis. Also, one of the Questions of the last ICOLD Congress of Beijing in the year 2000 dealt on “The use of Risk analysis to support dam safety decisions and management”.

All these considerations have given rise to the reassessing of the actual criteria, and to the development of new techniques and methodology in the field of dam safety, among which stand out the risk analysis and risk management, with more rational and objective schemes, which could constitute the base of the THIRD GENERATION CRITERIA for the selection of the design flood.

The risk analysis can be defined as a methodology to estimate risk from hazard, that is to say, a technique in order to quantify the hazard and calculate the risk of damages downstream in the case of failure of a dam, the risk being a measure of the probability and severity of an adverse effect. In the case of a dam PF is the annual probability of failure of the dam and CD are the consequences of the failure, the risk being the product of the probability and the consequences, R = PF x CD.

Within the dam safety the field of hydrological safety is that which best adapt to the risk analysis methodologies and criteria, based on the probabilities of events and consequences, principally in hydrologic safety standards based on probabilistic methods, since in this case exist a concordance in the probabilistic concepts. In the case of the deterministic approaches (PMF) it is necessary to convert the design flood into probabilistic terms, and usually a value of 10-6 is used for the PMF.

The basic criteria for the selection of the design flood within the risk analysis is that of the Acceptable Risk Criteria (ARC) or Society Acceptable Risk Criteria which is the risk that society is prepared to tolerate without having to carry out operations to reduce the risk. Its value can be shown in



a log-log plot (F-N Chart) of the annual probability of incremental loss of life versus the incremental number of lives that are expected to be lost due to the failure of the dam.

Figure 8. Indicative Acceptable Risk Criteria (ARC)

Figure 8 shows the criteria developed by various agencies or organizations (for example in the Netherlands for the risk in the polders, ANCOLD the Australian Committee of Large Dams, and a proposal of the Canadian company B.C. Hydro). One of the usual criteria for the loss of life is that of 10-3 life per year per dam, which divides the risk in the zones of unacceptable risk for values greater than 10-3, and in the zone of acceptable risk for values of less than 10-3. So, if this criteria were followed for a potential loss of lives greater than 1,000 lives, the design flood would be that corresponding to a return period of 10-6 years (or the PMF), and for 10 lives it would be 10-4. It can be observed that these criteria of risk analysis permit a continual discrimination of the hydrological safety in function of the potential number of loss of lives, with which criteria the approach is more rational and objective, demanding greater safety the greater the evaluation potential of lives. In any case the ARC supposes an interconnection between the deterministic and probabilistic approaches.

Nevertheless, it is very important to point out that in the field of safety of dams these ARC criteria are not well established in a definite manner and that in some cases, refers to all the types of failure and not only to the failures of a hydrological nature.

The actual state of the art of the Risk Analysis presents a series of problems and uncertainties which it is necessary to define and to channel in the future, among which the following points may be emphasised referring to the hydrologic safety:

1. In several formulations of risk analysis the existence of warning systems are taken into account, which can reduce in a very significant manner the value of the expected loos of life in relation to the population at risk. This problem was already equally raised in the dam hazard classification and in general the regulations and guidelines recommended not to take



into account, the existence of warning systems, with a view to the establishment of hydrological standards.

2. The application of the acceptable risk criteria could suppose a relaxation of the actual standards principally in the field of 1 to 1,000 potential fatalities, which implies lesser demands in the hydrological safety. For this motive, its principal field of application would be, in the first place, that of making it economically viable and determine the priorities in the accommodation of existing dams to the new demands of hydrologic safety,

3. In many countries the existing regulations prescribe the adoption of hydrological safety STANDARDS, for which for a progressive application of the criteria based on the risk analysis it is necessary to introduce this possibility in the regulations and guidelines.

In conclusion, the criteria based on the risk analysis suppose an important tool in the field of Hydrological Safety and permit a new vision of the hydrological risk which enlarges the field of the actual standards. For this, they could constitute the basis for the formulation of new criteria for the selection of the design flood. Nevertheless, it should be pointed out that these new criteria based on the Risk Analysis are still in a phase of permanent development and its use has been very limited to some cases without it having been totally extended. So, at the present time, the evaluations based on the Risk Analysis in general should not be considered as an alternative to the traditional criteria based on hydrological safety standards and the Dam Hazard Classification, but rather as a complement, having its principal application to the evaluation of the hydrological safety of existing dams.

REFERENCES Berga, L.(1998). New trends in hydrological safety. In Dam Safety, L.Berga (ed), 1099-1106.

Balkema, Rotterdam. Berga, L. (2000). Benefits of dams in flood control. R35. Q77. 20th. International Congress on Large

Dams. Beijing. Berga, L. (2000). Hydrological Risk Criteria. 20th. International Congress on Large Dams. Vol. V,

Beijing. IAHS. International Association of Hydrological Sciences Rodier, J.A., Roche, M. (1984). World

Catalogue of Maximum Observed Floods.. IAHS Publication Nº 143 ICOLD. (1995). Dam failures. Statistical Analysis. Bulletin 99. International Commission on Large

Dams. Paris. ICOLD. (2003). Dams and Floods. Guidelines and Case Histories. Bulletin 125. International

Commission on Large Dams. Paris. ISDR. (2002). International Strategy for Disaster Reduction. Living with risk. A global review of

disasters reduction initiatives. United Nations, Interagency Secretariat. Geneva. MUNICH RE. (2002). Topics. Annual review of natural disasters. Munich Re Group. München,

Germany. U.S.Army Corps of Engineers, (1997). Dam Safety Assurance Program. Engineer Regulation 1110-2-

1155. Washington DC. Zupka, D. (1998). Economic impact of disasters. UNDRO News. Jan-Feb. United Nations. Geneva.



upst. downst.

Acena Spain 65 I UD 1.3 1.3 0.3+0.003H 0.4 3+H/15 - Gneiss - -

Agbulu Philippines 234 P UD 1.4 1.5 - - - - - 21000 3981

Aguamilpa Mexico 187 P 1993 1.5 1.4 0.3+0.003H h0.3,v0.35 5-10 137Gravel/

ignimbrite12700 6950

Ahnning Malaysia 74 W/P 1988 1.3 1.3 0.3 0.61 6 16 Quartzite 700 235Aixola Spain 51 W 1982 1.35 1.3 1.45 - - - - 375 3

Alfilorios Spain 67 W 1990 1.4 1.35 0.30 - Gallery - Limestone 347 23

Alsasua Spain 50 W/I 1985 1.5 1.4 0.3+0.003H 0.4 4.5 14 Limestone - -

Alto Anchicaya

Colombia 140 P 1974 1.4 1.4 0.3+0.003H 0.5 7 22 Hornfels 2400 45

Amalahuigue Spain 60 - 1983 1.3 1.4 - - - - - 2.61 1

Ancoa Chile 130 I/P - - - - - - - - - -Andaqui Colombia 160 - Proposed - - - - - - - - -

Antamina Peru 109 Tailings 2002 1.4 1.4 0.3 0.35 3-11 67 Limestone 4.7 -Anthony Australia 39 P 1993 1.3 1.3 - - 3-4 4.4 - 110 39

Atasü Turkey 122 W/P (2002) 1.4 1.50.3+0.0035

H0.4 12 45 Andesite, basalt 3787 36

Awonga (raised)

Australia 63 I Proposed 1.3 1.3 0.3+0.002H 0.75 - 30 Meta Sediments - -

Babagon Malaysia 63 W 1996 1.3 1.6 - 0.3IS 3-5

- Sandstone, random - -

Badu China 58 I/W/F/P 1997 1.3 1.3 - - - 6 Tuff/lava 840 32

Bailey, R D USA 95 F/R 1979 2.0 2.0 0.3 0.5 3.05 65 Sandstone, Limestone - -

Baishuikeng China 101 P 2005 1.4 1.4 0.3-0.55 - 5-6 - Rockfill 1500 24.8

Baishui-Keng China 101 P 2005 1.4 1.4 0.3-0.55 - 5-6 - Rockfill 1500 25

Baixi China 123.5 W/I/P 2001 1.4 1.5 0.3+0.003H 0.4 5-8 48 Tuff lava 3700 168

Baiyanghe China 37 I 1994 1.7 1.5 0.3+0.003H 0.5 2,2.8,3.8 21 Gravel 370 6

Name Country Height (m) PurposeYear

completed Slopes Face slab

thickness Reinf each

way (%)Reservoir capacity

Plinth width (m)

Face area (103 m2)

Rockfill typeRockfill

volume (103



Baiyun China 120 P 1998 1.4 1.4 0.3+0.002H h0.35v0.4 4-5 15 Limestone 1700 360

Bajiaotan China 70 - Proposed 1.4 1.4 - - - - Shale - -

Bakun Malaysia 205 P UC 1.4 1.4 0.3+0.003H h0.3,v0.4 4,6,10 127 Greywacke 17000 43800

Balsam Meadows

USA 40 P 1988 1.4 1.4 - - - - Granite - -

Barra Grande

Brazil 194 P 2005 1.3 1.4

0.3+0.002H > 0.005H

0.4 - 0.5IS

4-10108 Basalt 12.000 5000

Barrendiola Spain 47 - 1981 1.6 1.5 - - - - - 270 2

Barrigon Panama 82 P 2003 1.45 1.6 0.3 3 GravelBasha Pakistan 200 P/I U/C - - - - Diaphragm - - - -

Bastonia Romania 110 - 1997 1.5 1.5 0.3+0.003H 0.5 4.6 30 Andesite - -

Bastyan Australia 75 P 1983 1.3 1.3 0.25 0.7 3 - 3.8 19 Rhyolite 600 124Batang Ai

(main)Malaysia 70 P 1985 1.4 1.4 0.3 0.5 4.6 65 Dolorite 4000 2360

Batubesi (Larona)

Indonesia 30 P 1978 1.3 1.5 0.25 0.3 4 - - - -

Bayibuxie China 35 I UC - - - - - - Gravel 200 4

Bejar Spain 71 I 1988 1.3 1.30.35+0.003

H0.4 3 - H/15 19 Granite 767 14

Berg River South Africa 70 I 2006 1.5 1.5 0.32+0.0024H 0.4 4-8 70 Gravel - -Beris Pakistan 40 P 2003 1.4 1.4 0.3+0,002H 0.4 - - Rockfil - -

Bocaina Brazil 80 P UD 1.3 1.3 - - - - - - -

Bolboci Romania 56 W/P 1985 1.3 1.3 0.3+0.007H 0.4 Gallery 6 Limestone 1000 18

Booan R.Korea 50 W/F/P/I 1996 1.4 1.40.3+0.0034

H0.4 3 18.2 Rhiolite 614 41.5

Boon (stage 2)

Australia 73 - Proposed - - - - - - - - -

Boondoma Nº 1

Australia 63 W/I 1983 1.3 1.3 0.3 0.4 3.5-5.5 25 Rhyolite - -



Bradley Lake

USA 40 P 1989 1.6 1.6 0.3 0.5 4-5 - Greywacke - -

Cabin Creek USA 76 P 1967 1.3 1.750.3+0.0067

H0.5 - - Rock & earth - -

Campos Novos

Brazil 200 P 2006 1.3 1.40.3+00.002

H 0,005H

0.4 - 0.5IS

4.5-12106 Basalt 12.500 1480

Caritaya Chile 40 I 1935 1.5 1.5 0.3-0.35 _ Trench 5 DR _ 42

Capillucas Peru 37 P UD 1.4 1.4 0.3+0.003H 0.35 3 6 Gravel 175 5.1

Caruachi Venezuela 80 P 1999 1.3 1.3 0.35 0.35 3 60 Granite, gneiss 2000 4Catemu Chile 79 I UD 1.5 1.6 0.3-0.47 _ _ 182 Gravel P.wall 10.010 175

Catlitkoru Turkey - I 2002 - - - - - - - - 49.5

Cengang China 28 W/I 1998 1.4 1.4 0.35 0.4 3 Diaphragm 11 Tuff 310 6

Cercado Colombia 120 I 2004 1.4 1.4 0.3+0.002H h0.35,v0.4 3-6 37 Vulcanite 2900 198

Cerna Romania 91 W/P/I 1980 1.3 1.3 0.4+0.002H 0.5 Trench 5.4 Limestone 487 124

Cethana Australia 110 P 1971 1.3 1.3 0.3+0.002H 0.6 3-5.36 24 Quartzite 1376 109

Chacrillas Chile 105 I UD 1.5 1.65 0.3-0.5 0.3-0.35 _ 34 Gravel 2.450 27

Chaishitan China 103 I/P 2000 1.4 1.4 0.3+0.003H - 6-7 38.2 CR - dolomite 2170 437

Chakoukane Morocco 63 I 1999 1.6 1.6 - - - -Gravel/

Diaphragm1800 50

Chase Gulch USA 40 W 1994 - - - - - - - - -

Chengbing China 74.6 P 1989 1.3 1.30.3+0.0027

Hh0.3,v0.5 3-12 15.85 CR - tuff 800 52

Chentianhe (raised)

China 110 P UD - - - 0.3-0.4 - - - 2500 1600

Cheong-Song S.Korea 54 P 2005 1.4 1.4 0.40 - 4 20 Rockfill 711 7Cheong-Song S.Korea 85 P 2005 1.4 1.4 0.40 - 6 34 Rockfill 2145 7

Chihuiido Argentina - P U/D - - - - - - - - -



Chong Song Lo

R.Korea 52 p 2005 1.4 1.4 0.3+0.003H 0.4 4-6 19.6 Gravel 711 6.5

Chong Song Up

R.Korea 95 p 2001 1.4 1.4 0.3+0.003H 0.4 4-6 34.4 Gravel 2144 6.5

Chusong China 40 P/I 1999 1.8 1.3 0.3 0.4 Diaphragm - Sandy-Gravel 700 15

Cirata Indonesia 125 P 1987 1.3 1.40.35+0.003

H0.4 4,5,7 - Breccia/ andesite 3600 2160

Cirata (raised)

Indonesia 140 P/F Proposed - - - - - - - - -

Cogoti Chile 85 I 1939 1.4 1.5 0.2+0.008H - Trench 16 DR 700 150

Conchi Chile 70 I 1975 1.5 1.5 0.25-0.50 _ Trench 10 - 450 22Cogswell USA 85 F 1934 1.35 1.6 0.3 - Trench - DR - granite 799 13Corrales Chile 70 I 2000 1.5 1.6 0.3-0.5 0.4-04 3-4 29 Gravel 1600 50Corumbel

BajoSpain 46 - 1987 1.5 1.5 - - - - - 480 19

Courtright USA 98 P/I 1958 1-1.3 1.30.3+0.0067

H0.5 Trench - DR - granite 1193 152

Crotty Australia 82 P 1990 1.3 1.5 0.3 0.5 3-4.2 13 Gravel quartzite 784 1060

Daao China 90 I/F/P 1999 1.4 1.4 0.3+0.002H 0.27-0.47 4-6 26 CR - sandstone 1450 278

Daegok S.Korea 52 W 2003 1.4 1.8 0.30 0.4 4-5 27 Gravel-shale 580 28Dahe China 68 P/F 1999 1.4 1.4 0.4 0.4 3-5 - Limestone 900 332

Daiqiao China 91 W/I/P 1999 1.5 1.7 0.4 0.3 6-9 30 CR 2090 658Daliushu China 156 I/P UD 1.6 1.4 - 1.7 0.3-0.8 0.35 6-10 164 Sandstone 1450 98.6

Danzitai China 61.8 I/W/P 1999 1.35 1.35 0.4 0.4 4 35.8CR - sandstone,

mudstone630 11.5

Dashuigou China 76 P/I 2004 1.4 1.4 - - - - CR 750 3.1Dchar El

OuedMorocco 101 I/P (2001) 1.4 2.1 0.3+0.003H 0.3 4-5 -

Quartzites Psammites

2000 740

Dhauliganga India 50 P (2003) - - - - Diaphragm - Gneiss - -

Diguillin Chile 92 I UD 1.5 1.6 0.3+0.002H 0.3- 0.35 5 42 Gravels 2.050 80

Dim Turkey 135 I/P/W (2001) 1.4 1.50.3+0.0035

H0.4 13 51 Schist 4093 250



Dix River USA 84 P 1925 1-1.2 1.4 - 0.5 Trench - DR - limestone 252 220

Donbog R. Korea 45 W 1985 1.5 1.5 0.3+0.008H 0.5 5-3 7 Andesite 420 100

Dongjin China 89 W/P/I 1995 1.4 1.30.3+0.0023

H0.4 4-8 28 Sandstone 1760 800

Douling China 89 P/I/W/F 2001 1.4 1.6 - - - 32 Limestone, phyllite 2240 485

Douyan China 53 P 1995 1.4 1.6 0.3 h0.34,v0.52 4-5 18.7 CR - granite 520 98

Duqiang China 89 I/P/W 2005 1.3 1.3 0.3-0.5 0.3-0.4 3-5 18 Tuff 950 15El Bato Chile 55 I U/C 1.5 1.6 0.34-045 - 3-5 52 Gravel P.wall 2.380 25

El Cajon Mexico 189 P UC 1.5 1.4 0.3+0.003H 0.4% - 99 Ignimbrite 12000 1604

El Tejo Spain 40 I/P/W 1974 1.4 1.3 0.25 0.25 Gallery 9 limestone 210 1.2

Fades France 70 P 1967 1.3 1.30.35+0.0042

H0.5 4 17 Granite, - -

Fantanele Romania 92 P/F 1978 1.3 1.3 0.3+0.007H 0.5 Gallery 34.2 Granite, 2320 225

Fenes Romania 40 W/F UD 1.6 1.5 - - Trench 5 granite 245 6.5Fengning China 39 P 2001 2.0 1.7 - - - - sandy - gravel 570 72

Fortuna Panama 65 P 1982 1.3 1.4 0.41+0.003H 0.5 4 22 Andesite - -

Fortuna (raised)

Panama 105 P 1994 1.3 1.40.30

shotcrete0.25 4 - Andesite - -

Foz do Areia Brazil 160 P 1980 1.4 1.40.3+0.00357

H0.4 4 - 7.5 139 basalt 14000 6100

Francis Creek

Australia - I 1997 1.3 1.3 - 0.3 3-5 - - - -

Gandes Francia 44 - 1967 1.6 1.3 - - - - - - -

Gangkouwan China 70 F/P/I 1999 1.4 1.4 - - 4.5 18.3 quartzsand st. 1020 958

Gaotang China 110.7 P 1999 1.4 1.36 - 0.4-0.5 8 26.4 Granite 1950 96Glennies Creek

Australia 67 W/I 1983 1.3 1.3 0.3 0.43 3-4 25 welded tuff 947 284

Gojeb Ethiopia 130 P UD 1.3 1.5 0.3+0.003H 0.4 - - limestone - -



Golillas Colombia 125 W/P 1978 1.6 1.60.3+0.0037

H0.4 3.0 14.3 gravels 1.3 252

Gongboixia China 130 P 2007 1.4 1.4 0.3+0.003H 0.4 4-8 46 granite gravels 4550 550

Gördes Turkey 95 I/W (2001) 1.4 1.50.35+0.003

H0.4 9 61 limestone 4700 450

Gouhou China 70 W/I 1989 1.6 1.55 0.3+0.004H h0.35,v0.5 4-5 22 sandygravel 890 3

Guadalcacin Spain 78 - 1988 1.5 1.5 - - - - - 1098 800

GuaigunDominican Republic

75 W 2006 - - - - - - - - -

Guamenshan China 59 W/F/I/P 1988 1.4 1.3 0.3+0.003H 0.38 3-5 8.2 Andesite 440 81

Guangzhou (upper)

China 68 P 1992 1.4 1.4 0.3+0.003H 0.4 3-6 17.7 cr-granite 900 17

Gudongkou China 120 I/F/P 2000 1.4 1.5 0.3+0.003H h0.4,v0.5 4.5-10 5.5-9.5 gravel limeston. 1900 138

Haichaoba China 57 I 1996 1.4 1.3-1.4 0.35 h0.4,v0.5 4-5 12.8 gravel gneiss 480 7.4

Heiquan China 124 W/I/P 2000 1.55 1.40.3+0.0035

Hh0.3,v0.4 4-7 79 cr-tuff lava 5500 182

Hengshan (raised)

China 70 W/I/P 1992 1.4 1.3 0.3 0.4 4.4 10.35 limestone 1090 112

Hongjiadu China 182 P 2007 1.4 1.4 0.3+0.003H 0.5 6-10 76 cr-limestone 10000 4590

Hongzhuhe China 52 I 1997 - - - - - - cr-limestone 220 -Houay Ho Laos 85 P 1996 1.4 1.5 0.3 0.52 4-9 22 sandstone 1250 595Huallaga Peru 140 P/F Proposed - - - - - - - - -Huangliao China 40 P/F - 1.4 1.4 0.25 0.35 3 2 tuff - -

Huashan China 80.8 P 1993 1.4 1.4 0.3+0.003H h0.4,v0.5 3-6 13.03 cr granite 700 63

Ibag-Eder Spain 65 W 1991 - - - - - - - 750 11.3Ibba Yeder Spain 66 - UD 1.35 1.5 - - - - - - -

Ikizdere Turkey 108 I/W UC - - - - - - - - -Illapel Chile 55 I UD - - - - - - - - -

Ishibuchi Japan 53 - 1953 1.2 1.4 - - - 12 dr - Dacite - -



Ita Brazil 125 P 1999 1.3 1.3 0.3+0.002H h0.3,v0.4 IS 4-6 110 basalt 9300 5100

Itapebi Brazil 120 P 2003 1.25 1.3 0.3+0.002H h0.35,v0.4 IS 4-6 59 gneiss-micaschist 4100 1650

Jiemian China 126 P/I/F UD - - - - - 58 sandstone 3420 1058

Jilingtai China 152 P 2007 1.5 1.5 0.3+0.003H h0.5,v0.4 6-10 127 Tuff 9200 24.4

Jishixia China 100 P UD 1.5 1.55 0.3+0.003H h0.4,v0.5 4,6,7.4 - gravel-ballast 2880 264

Kaeng Krung Thailand 110 P/I Proposed 1.3 1.3-1.5 0.3 - - - - - -

Kalangguer China 61.5 P/F/W/I 2002 1.5 1.4 0.3+0.003H h0.4,v0.5 5-6 35.5 cg/cr gravel andesite 1200 39

Kaliwa Philippines 100 - UD - - - - - - - - -Kangaroo

CreekAustralia 59 W/F 1968 1.3 1.4 0.3+0.005H 0.5 3.7 8 schist 355 19

Kannaviou Cyprus 75 I UC 1.4 1.8 0.3+0.002H 0.4 IS 3-12 - - 1900 18

Karahjukar Iceland 190 P UD 1.3 1.3 0.3+0.002H h0.3,v0.4 4 - basalt 9600 2100

Karaoun Lebanon 66 - 1963 1.3 1.1 - - - - - - -Kavar Iran 60 - UD 1.4 1.7 - - - 35 - - -

Kekeya China 42 I 1986 1.2-2.75 1.5-1.75 0.3-0.5 - 3 Diaphragm 12 gravel 440 12

Khao Laem Thailand 130 P 1984 1.4 1.4 0.3+0.003H 0.5 4.5 (Gallery) 140 limestone 8000 -

Koi India 167 P/I U/C - - - - - - - - - Koman Albania 133 P 1986 - - - - - - - - -

Kootenay Canal

Canada 37 - 1975 2.0 1.3 0.20 0.6 2-4 20 gneiss 3000 -

Kotmale Sri Lanka 97 P 1985 1.4 1.45 0.3+0.002H 0.65 3-8 60 gneiss charnockite - -

Kürtün Turkey 133 P (2001) 1.4 1.5 0.3+0.003H 0.4 10 35 granodiorite 3026 108

Kwai Nai-Main

Thailand 95 I (2002) 1.4 1.4 - - - - - - -



La Joie Canada 67 P 1955 1.1 1.5 Shotcrete - Trench - DR - -

La Parota Mexico 155 P Proposed 1.5 1.4 0.3+0.003H - 4-8 170 gravel gneiss 12000 6752

La Regadera II

Colombia 90 W (2004) 1.5 1.6 0.3+0.002H h0.3,v0.35 3 - gravel - -

Laredo Spain 40 - Proposed 1.3 1.5 - - - - - - -

Lesu Romania 61 - 1973 1.3 1.3 0.3+0.007H 0.5 Trench 5 Riolite 560 28

Lianghui China 35 W/I/F/P 1997 1.4 1.4 0.35 0.83.5-4.5

Diaphragm22 Gravel 680 31

Liangjiang China 55 P 1999 1.4 1.3 0.3-0.5 - 4 20.6 cr granite 788 210

Lianhua China 72 P/F/I 1997 1.4 1.4 0.3+0.003H h0.4,v0.5 4-6 75 granite 4230 4180

Little Para Australia 54 W 1977 1.3 1.40.3+0.0029

H0.5 4 10 Shale dolomite 265 21

Longxi China 58.9 I/F/P 1990 1.3 1.3 0.4 h0.3,v0.5 3-5 7.07 Cr- tuff lava 300 26Los

CampitosSpain 54 - 1974 1.35 1.4 0.3 0.4 - 28 basalt 576 3

Los Caracoles

Argentina 131 P/I UC 1.5 1.7 0.3+0.002H h0.35,v0.4Diaphragm

4.0 IS- Gravels 9000 -

Los Molles Argentina 46 I UD 1.5 1.5 0.3+0.003H - 6 12 gravels 730 20

Lower Bear Nº 1

USA 71 P 1952 1.3 1.40.3+0.0067

H0.5 Trench 6 DR- Gravels 1002 6.4

Lower Bear Nº 2

USA 50 P 1952 1 1.40.3+0.0067

H0.5 Trench 3 DR Granite - -

LunggaSolomon Islands

- - Proposed - - - - - - - - -

Luochun China 57.5 I 1990 1.2 1.2-1.4 0.3 h0.4,v0.5 5-6 12.15 Dr sandstone 640 21Lyell Australia 46 W 1982 - - - - - - - - -

Machadinho Brazil 125 P 2002 1.3 1.3 0.3+0.002H h0.35,v0.4 IS 3-6 93 basalt 6800 -



Mackintosh Australia 75 P 1981 1.3 1.3 0.25 0.7 3.0-3.86 27 Greywacke 850 949

Madan Bulgaria 91.5 P U/C - - - - - - - - -Malpaso Peru 78 - 1936 0.5 1.33 - - Trench - Placed DR - -

Mangrove Creek

Australia 80 W 1981 1.5 1.60.375+0.003

H0.35 3,4,5 29 Siltstone 1340 170

Mangrove Creek

(raised)Australia 105 W Proposed 1.5 1.6 0.3+0.003H 0.35 3,4,5 34 Siltstone - -

Marmoris Turkey 80 - UD - - - - - - - - -Mashagou China 81 W 2003 1.4 1.5 0.3-0.57 - 8.5 16 Cr- Sandstone 700 6.7Matuola China 36 - 2001 - - - - - - - - -Mazar Equador 185 P 2006 - - - - - - - - -

M'Dez Morocco 97 I/P Proposed 1.8 1.6 0.3+0.003H 0.3 3-5 40 Gravel 1900 600

Meixi China 38 I 1997 1.4 1.3 0.35 0.4 Diaphragm 37 Tuff 1200 265Merowe (Nile)

Sudan 60 I/P 2009 1.3 1.4 0.3+0.003H h0.3,v0.4 4-15 - Granite - -

Messochora Greece 135 P/I 1995 1.4 1.4 0.3+0.003H 0.5 3-7.5 51 limestone - 650

Milyang R.Korea 89 W/F/P/I 2001 1.4 1.4 0.3+0.003H 0.45 5-8 54 Andesite 3763 73.6

Mironi Pakistan 127 I 2005 1.5 1.6 - - - - Gravel - -Mirza-Ya-

ShiraziIran 65 I UD - - - - - - - - -

Mohale Lesotho 145 I/P 2002 1.4 1.40.3+0.0035

H0.4 IS 3+H/15 87 basalt 7400 938

Mohammed BAK

Moroco 40 W/I 1981 1.9 2.2 0.3 0.4 Diaphragm 23 Basalt gravel 650 36

Monjolinho Brazil 74 P 2006 1.25 1.30.30+0.002

H 0.40-0.50 4 - Basalt 1.800 150

Morena USA 54 W 1895 0.5-0.9 1.30.23+0.003

H0.5 Trench - DR Granite 256 61

Morro de Arica

Peru 220 P UD 1.4 1.4 0.3+0.003H 0.4 3,5,10 38 Sandstone quartzite 5100 -

Motuola China 36 - UC - - - - - - - - -



Mukorsi Zimbabwe 90 I (2002) 1.3 1.3 0.4 0.5 4+H/30 22.3 Gneiss 2440 1802Mulagua Spain 56 I 1981 1.3 1.3 - - - 9 - 212 -

Murchison Australia 89 P 1982 1.3 1.3 0.3 0.65 3-4.6 16 Riolite 905 97

Murum Malaysia 141 P Proposed 1.4 1.4 0.3+0.003H 0.35 3-15 74 Greywacke 6600 12043

Nam Khek Thailand 125 P/I Proposed 1.4 1.5 - 0.4 4-7 59 Conglomerate - -Nam Ngum

3Laos 220 P (2005) 1.4 1.4 0.3+0.003H h0.3,v0.4 4-11 5 sandstone - -

Namgang R.Korea 34 W/R/P/I 1999 1.5 1.5 0.35 0.5 5 41.8 Gneiss 1280 309Nanche China 64 I/P/F 1996 1.4 1.4 0.3-0.45 0.425 3.5-5.5 12.4 Cr- Sandstone 460 153

Narmashir Iran 115 I 2008 1.5 1.8 - 0.4 4-7.5 58 Basalt Gravel 6000 180

Neveri Turimiquire

Venezuela 115 W 1981 1.4 1.5 0.3+0.002H 0.5 h3.5,v7.50 53 limestone - -

New Exchequer

USA 150 P/W/I 1966 1.4 1.40.3+0.0067

H0.5 3-4 - DR- Et- Cr 3952 1265

Nogoli Argentina 60 W/I UC - - - - Diaphragm - - - -Oasa Romania 91 - 1979 1.3 1.6 0.6 0.5 Gallery 24 Schist 1600 136

Odeleite Portugal 61 W/I 1988 1.4 1.4 0.5+0.005H 0.5 - - Schist- Greywacke 1000 130

Outardes Nº 2

Canada 55 P 1978 1.4 1.4 0.3 0.45 3.05 8 Gneiss - -

Peace S. Korea 80 F 1980 - - shotcrete - - - - - -

Peace raise S. Korea 105 F U/C - - - - - - - - -

Pai Querê Brazil 150 P 2008 1.3 1.40.30+0.002H 0.005H

0.4-0.5 - IS 4-8 Basalt 7 2600

Pankou China 123 P UD 1.4 1.50.3+0.0038

H0.5 4-7.5 46 limestone 3460 2460

Panshitou China 101 W/F/I/P 2005 1.4 1.5 0.3-0.5 h0.3,v0.4 - 75 sandstone - Shale 5290 679

Paradela Portugal 112 P 1955 1.3 1.30.3+0.00735

H0.5 Trench 55 DR- Granite 2700 165

Pecineagu Romania 105 W/P/I 1984 1.7 1.70.35+0.0065

H0.4 Gallery 30 quartzite 2400 69



Pichi Picun Leufu

Argentina 50 P 1995 1.5 1.5 0.35 h0.3,v0.35 4 - Gravels 1370 -

Piedras Spain 40 W/F 1967 1.3 1.3 0.25 0.5 4 16.5 Sandstone 380 60Pindari (raised)

Australia 83 I/F/W 1994 1.3 1.3 0.3 0.3 4 - Ryolite 2695 312

Pingtan China 55 I/W 1998 1.3 1.3 0.35 - - - - 390 11Pinzanes Mexico 67 P 1956 1.2 1.5 - - Trench - Tailings 3.08 4

Pipay-Guazu 2

Argentina 73 - Proposed 1.3 1.3 0.3+0.004H - - - - - -

Poneasca Romania 52 W/P UD 1.3 1.4 0.3+0.001H 0.5 2.5 5.2 Limestone 1000 8

Porce III Colombia 145 P -Potrerillos Argentina 116 P (2004) 1.5 1.8 - - - - - 6400 -Poyibuxie China 35 - 1997 - - - - - - Sandy-Gravel 200 4Puclaro Chile 83 I 2000 1.5 1.6 0.3-0.45 0.3 3-4 68 Gravels panel wall 4.800 200Punilla Chile 136 IHR U/D 1.5 1.6 0.3-0.66 0.3-0.4 4-7 84 Gravel 6.320 600

P.del viento Chile 105 I U/D 1.5 1.6 0.3-0.55 - - 48 Gravel 3060 85

Punta Negra Argentina 86 I/P (2004) 1.65 1.4 0.3+0.002H -4-6 IS

Diaphragm - Gravel 7300 -

Pyonghwa R. Korea 80 F 1988 1.5 1.5 0.7-1.0 0.5 8.5-11.5 45.3 Gneiss 2737 5.9

Qiezishan China 104.5 I/P 1999 1.4 1.4 0.3+0.003H h0.3,v0.4 5-7 26.4 CR - granite 1400 121

Qinshan China 122 I/P 2000 1.4 1.35 0.3+0.003H 0.5 5,6,8 42 CR - tuff 3100 265

Quebra-Queixo

Brazil 75 P 2003 1.25 1.3 0.3+0.002H 0.4-0.5 4-5 49 Basalt 2200 137

Quimbo Colombia 150 P Proposed 1.5 1.6 - - 4-10 - Gravel 7130 -

RamaBosnia

Herzegovina110 - 1967 1.3 1.3 - - - - - 1340 487

Rastolrita Romania 105 P/W 1997 1.5 1.5 0.3+0.003H 0.5 4-6 30 Andesite 3100 43

Reece (Lower Pieman)

Australia 122 P 1986 1.3 1.3-1.5 0.3-0.001H 0.65 3-9 37.8 Dolerite 2700 6411

Roseau - 40 W 1995 1.3 1.5 0.3 0.33 3.3 6.8 Andesite - -



Rouchain France 60 - 1976 1.4 1.40.35+0.0042

H0.5 4 16 Granite - -

Rubiales Romania 43 - 1977 1.4 1.4 - - - - Peridotite - -Ruiqiang 2 China 89 I/F/P 2005 1.3 1.3 0.3-0.5 h0.3,v0.4 3-5 18.1 CR- tuff lava 950 15

Runcv Romania 90 W/P 1999 1.4 1.4 0.3+0.002H 0.45 4 26.2 Granite 1900 26

Salt Springs USA 100 P/W 1931 1.1-1.4 1.40.3+0.0067

H0.5 Trench 11 DR - granite 2294 171

Salvajina Colombia 148 P/W 1983 1.5 1.4 0.3+0.0031H 0.4 4-8 57.5Dredger tailings,

greywacke4100 906

San Anton Spain 68 - 1983 1.35 1.35 - - - - - 434 12San

IldefonsoMexico 62 I/F 1942 1.4 1.4 - - Trench - Basalt 3.70 63

San Marcos Spain 33 - 1998 1.4 1.4 0.3 0.4 2 5 Granite 434 12

Sanbanxi China 179 P 2008 1.4 1.40.3+0.0035

H0.4 6-12 94 Sandstone 994 41.70

Sanchaxi China 88.8 - 1999 - - - - - 13.8 CR 771 47

Sancheng 1Korea

(Rep of)65 P 2002 1.4 1.4 0.3+0.002H h0.35,v0.48 4-7 31.7 Granite 2163 63

Sancheng 2Korea

(Rep of)90 P 2002 1.4 1.4 0.3+0.002H h0.35,v0.48 4-7 23 Gneiss 1690 7.1

Sanguozhuang

China 62.8 I/P/F 2000 - - - - - 20 CR - basalt 800 15.4

Santa Juana Chile 113 I 1995 1.5 1.6 0.3+0.002H 0.3-0.3 3-5 39 Gravel, panel wall 2700 160

Santa Rita Brazil 85 P UD 1.3 1.3 - - - - - - -

Segredo Brazil 145 P 1992 1.3 1.2-1.40.3+0.0035

H0.3,0.4 4-6.5 86 Basalt 7200 3000

Shakaoukane Morroco 63 I 1999 1.6 1.6 - - Diaphragm - - 1800 50Shankou China 39 P/I 1996 1.4 1.4 0.3 0.4 3 9 Tuff 650 46

Shanxi China 131 P 2001 1.6 1.5 0.3+0.003H 0.4 6-10 61 Rhyolite, gravel 5000 1922

Shapulong China 64.7 P 2001 1.3 1.3 0.4 - 4-5 7 Lava/limestone tuff 450 8.5

Shedong China 50 P/I UC - - - - - - CR - 8



Shewang China 36 P/I/F 1994 1.3 1.30.15-

Shotcrete- 4 7 Tuff 120 3

Shiroro Nigeria 130 P 1984 1.3 1.3 0.3+0.003H 0.4 6 50 Granite 3900 7000

Shisanling (upper)

China 75 P 1994 1.5 1.7 0.3 h0.5,v0.6 - 32CR - limestone

andesite2700 4

Shuanggou China 110 P UD 1.4 1.4 0.3+0.003H h0.3,v0.4 3.5-5.5 41 Andesite, basalt 2580 391

Shuibuya China 232 P 2009 1.4 1.46 0.3+0.003H 0.4 4-10 120 Limestone 16700 4700

Siah Bishe (lower)

Iran 130 P UD 1.5 1.6 - - - - Limestone, basalt - -

Siah Bishe (upper)

Iran 100 P UD 1.5 1.6 - - - - Dolomite - -

Sianjiang China 103 W/F 2004 1.4 1.46 0.3-0.65 6-10 75 CR 2100 89Siang Middle

India 190 I P UD - - - - - - - - -

Sierra Boyera

Spain 32 W 1973 1.3 1.3 0.3 0.45 Gallery 8 Limestone 380 41

SilanJiang China 103 W 2004 1.4 1.46 0.3-0.65 - 6-10 75 Rockfill 2100 89

Sogamoso Colombia 190 P (2005) 1.4 1.4 0.3+0.003H h0.3,v0.4 6-10 75 Sandstone Gravels - -

Songshan China 78 P 1999 1.4 1.4 0.3+0.003H 0.5 6-8 23.6 CR - andesite 1420 123

Souapiti Guinea 125 P Proposed 1.7 1.8 0.3+0.003H - - - Gravel - -

Spicer Meadow

USA 82 P 1988 1.4 1.4 0.3+0.003H - 0.4 6 Granite - -

Split Rock Australia 67 I 1987 1.3 1.3 0.3 0.35 - - Greywacke/gravel 1048 398Storvas Norway 80 P 1980 1.3 1.3 - - - - - - -

Strawberry USA 50 P/W 1916 1.1-1.2 1.30.23+0.003


Suojinshan China 62 P/I/F UC - - - - - - - 600 100

Surduc Romania 37 W/I/F 1976 1.5 1.5 0.4+0.005H 0.5 Trench - Schist 125 56

Taia Romania 64 - UD 1.65 1.55 - - Gallery 9.7 Schist - -



Taián Upper China 40 P 2006 1.3 1.3 - - - - - -

Tamjin R Korea 53 W/F/P/I 2003 1.4 1.4 0.3+0.003H 0.4 4-6 26 Tuff 1506 183

Tankeng China 161 P UD 1.4 1.4 0.3+0.003H 0.4 6-10 68 Tuff 10000 35.3

Tanzitan China 62 1999 1.35 1.35 0.4 0.4 4 36 Sandstone 630 12Taoshui China 103 - UD 1.4 1.55 - - - 29 - 1720 52Tasite China 43 I 1999 1.6 1.6 - - Diaphragm - Sandy-Gravel 450 12

Terror Lake USA 58 - 1985 1.5 1.4 0.3+0.003H 0.4 - - Greywacke - -

Tetelcingo Mexico 150 P Proposed 1.5 1.4 0.3+0.003H - - - Gravels - -

Tianhuangping Lower

China 95 P 1997 1.4 1.3 0.3+0.002H 0.4 6-10 21 Rhyolite, tuff lava 1420 9

Tianshengqiao Nº 1

China 178 P/I/F 1999 1.4 1.4 0.3+0.003H h0.3,v0.3 4-9 180 Limestone 18000 10260

Tocoma Venezuela 40 P 2009 1.3 1.3 0.35 h0.3,v0.35 3 - Gneiss - -Tongbai,

lowerChina 71 P 2007 1.4 1.35 0.3+0.003H 0.5 3.5-5 38 CR- tuff lava 1500 12.9

Tongjiezi Saddle

China 48 P 1992 1.75 1.7 0.3-0.4 h0.42,v0.63 2.5-3 16 Gravel/Basalt 700 200

Tongpu, west

China 37 W 2000 1.4 1.4 0.3 0.45 Diaphragm 9.3 Rockfill 500 235

Tongpu, west China 37 W 2000 1.4 1.4 0.30 0.45 Diaphragm 9.3 Rockfill 500 235

Torata Peru 100 W/I 2000 1.6 1.4 0.3+0.002H 0.4 4 21 Limestone 2000 3

Torata stage II

Peru 130 F/I 2001 1.6 1.4 0.3 0.4 4 54 Mine waste 7000 19

Toulnoustoc Canada 76 p 2006 - - - - - - - - -

Truro Peru 50 - 1988 1.5 1.5 0.4 0.5 3-5 - Breccia - -

Ulu Al Malaysia 110 P 1989 1.3 1.4 - 0.61 6 48Greywacke/ sandstone

- -

Undurraga Spain 36 W 1973 1.75 1.4 0.25 0.45 Gallery 7 Limestone 325 2Urkulu Spain 52 W 1981 1.6 1.4 0.3 0.35 Gallery 9 Limestone 350 10



Vilar Portugal 55 P 1965 1.1-1.3 1.30.3+0.00735

H0.5 - - DR - granite 300 100

Villagudin Spain 33 - 1981 1.3 1.3 - - - - - 250 18.3

Wananxi China 93.5 P 1995 1.4 1.4 0.3+0.002H h0.35,v0.4 4-5 18 CR - granite 1290 228

Wawushan China 140 I/P UD - - - - - - - - 545

West Seti Nepal 190 P UD 1.45 1.65 0.3+0.003H 0.4Diaphragm 4-

11- Gravel 12500 1604

White Spur Australia 45 P 1988 1.3 1.3 0.25 0.5 3-4.2 5 Tuff - -

Winneke/ Sugarloaf

Australia 85 W 1979 1.5 2.2 0.3+0.002H 0.45 0.1H 83 Sandstone 4700 100

Wishon USA 82 P/I 1958 1-1.3 1.40.3+0.0067


Wuluwati China 138 F/I/P 1998 1.6 1.6 0.3+0.003H h0.4,v0.5 6-10 72.2 CG/CR gravel/schist 6800 340

Xe Kaman Laos 187 P Proposed 1.3 1.3 0.3+0.002H h0.35,v0.4 4-9 84 Sandstone 9200 17330

Xe Kaman (2nd stage)

Laos 200 - Proposed 1.3 1.4 - - - - Mine tailings dam - -

Xe Nammoy Laos 78 P UD - - - - - - - - -

Xe Namnoy Laos 78 P Proposed - - - - - - - - -

Xepain-Xenamnoy

Laos 78 p 2008 - - - - - - - - -

Xiangshuijian

China 153 P UD 1.4 1.4 - - - - - 2570 17

Xiantianji China 82 - 2001 - - - - - - - - 19Xiaoba China 65 P/I 2000 - - - - - - Rockfill 710 13

Xiaogangou China 55 P 1990 1.55 1.6 0.3 0.55 3.5-4.5 5.18 CG - gravel 240 10

Xiaolingtou China 36 - 1995 - - - - - - - - -

Xiaomeisha China 49 W 1995 1.4 1.4 0.35 0.4 3-4 6 Granite 220 1.5



Xiaoshan China 86 P 1997 1.4 1.4 0.3+0.003H h0.4,v5 6-8 36 Andesite 1430 97

Xiaoxikou China 68 I/P 1999 1.4 1.3 0.4 - 6 20 CR - limestone 1110 66.4

Xibeikou China 95 P/I/F 1990 1.4 1.4 0.3+0.003H 0.4 5-6 29.5 CR - limestone 1620 210

Xikou lower China 44 P 1997 1.4 1.5-1.6 0.3 0.43 4 11 Lava-Tuff 1420 57

Xikou Upper China 48 P 1996 1.4 1.3-1.4 0.3 0.426 4 9 Conglomerate/Tuff 650 46

Xingó Brazil 150 P 1994 1.4 1.30.3+0.0029

H0.4 5-7 135 Granite gneiss 12300 3800

Yacambu Venezuela 162 W 1996 1.5 1.6 0.3+0.002H 0.4 - 13 Gravels - 435

Yang YangKorea

(Rep of)93 P 2005 1.4 1.4 0.3+0.003H 0.4 4-5 26 Gneiss 1400 0.5

Yaojiaping China 180 P UD - - - - - - - - -Yaoshui China 103 - UD 1.4 1.55 - - - 29 - 1720 52

Yedigaze Turkey 105 - UD - - - - - - - - -Yesa Spain 117 I/P 2006 1.5 1.6 0.3 0.4 8 44 Gravels 4394 17

Yingchuan China 87 - 2001 - - - - - - - 1100 -Yinzidu China 135 P 2005 1.4 1.48 - - 7-9 42.3 Limestone 3300 527

Yongdam R. Korea 70 W/F/P/I 2001 1.4 1.4 0.3+0.003H 0.5 5-8 43 Schist 2198 815

Yubeishaan China 72 - 1999 - - - - - 38 CR 890 860

Yunqiao China 83 P 2001 - - - - - - - 1500 10Yushugou China 67.5 I 2000 1.4 1.4 0.3,0.4 CR 570 11

Yutiao China 110 W/P/I 2002 - - - 30 Sandstone 1630 95Zeya China 79 W/F/P 1997 1.3 1.3 0.4 0.4 3.5-6 - Tuff 1420 57

Zhushuqiao China 78 I/F/P 1990 1.4 1.7 0.3+0.003H h0.35,v0.4 3.5-5 23 CR slate/limestone 820 278

Zipingpu China 159 P 2007 1.4 1.5 0.3+0.003H - 5,8,15 127 Sandstone 11670 1080

- Not available



Purpose Year completed or expected (%) Reinf each way Plinth width Rockfill typeP: Hydropower UC: Under Contruction h: Horizontal IS: Internal Slab CR: Compacted RockfillI: Irrigation UD: Under Design v: Vertical DR: Dumped RockfillF: Flood Control n/s=year notsupplied CG: Compacted GravelW: Water SupplyR: RecreationH=dam height



Rockfill ReservoirName Country Height Purpose Year Slope Face slab t Reinforcing Plinth Face area Type Volume capacity

m Completed US DS =m+CH each way width, m 10^3 m^3 10^3 m^3 10^3 m^3

Morena Calif, USA 54 W 1895 0.5-0.9 1,3 0.23+0.003H 0,5 T DR-granite 256 61Strawberry Calif, USA 50 P/W 1916 1.1-1.2 1,3 0.23+0.003H 0,5 T DR-granite 1343 229Dix River Kentucky,USA 84 P 1925 1-1.2 1,4 0,5 T DR-limestone 252 220

Salt Springs Calif, USA 100 P/W 1931 1.1-1.4 1,4 0.3+0.0067H 0,5 T 11 DR-granite 2294 171Cogswell Calif, USA 85 F 1934 1,35 1,6 0,3 T DR-granite 799 13Malpaso Peru 78 1936 0,5 1,33 T Placed & DR Cogoti Chile 75 I 1939 1,6 1,8 0.2+0.008H T 16 DR-gravelSalazar Portugal 70 1949 1,25 1,4 Steel G DR-siliceous

shaleLower Bear No.1 Calif, USA 71 P 1952 1,3 1,4 0.3+0.0067H 0,5 T 6 DR-gravel 1002 6,4Lower Bear No.2 Calif, USA 50 P 1952 1.0 1,4 0.3+0.0067H 0,5 T 3 DR-granite

Ishibuchi Japan 53 1953 1.2 1,4 12 DR-daciteLa Joie Canada 67 P 1955 1.1 1,5 Shotcrete T DRNozori Japan 44 1955 1.3 1,5 0.3+0.011H 0,5 T DR-andesite

Paradela Portugal 112 P 1955 1.3 1,3 0.3+0.00735H 0,5 T 55 DR-granite 2700 165Pinzanes Mexico 67 P 1956 1.2 1,3 TCourtright Calif, USA 98 P/I 1958 1.0-1.3 1,3 0.3+0.0067H 0,5 T DR-granite 1193 152Wishon Calif, USA 82 P/I 1958 1.0-1.3 1,4 0.3+0.0067H 0,5 T DR-granite 2829 158

San Ildefonso Mexico 62 1959 1.4 1,4Nakhla Morocco 46 W 1961 1.0 1,45 0,3 9 Poor sandstone

Karaoun Lebanon 66 1963 1.3 1,1

Vilar Portugal 55 P 1965 1.1-1.3 1,3 0.3+0.00735H 0,5 DR-granite 300 100New Exchequer Calif, USA 150 P/W/I 1966 1.4 1,4 0.3+0.0067H 0,5 3-4 DR & CR- 3952 1265

metamesiteCabin Creek Colorado, USA 76 P 1967 1.3 1,75 0.3+0.0067H 0,5 Rock & earth

Fades France 70 P 1967 1.3 1,3 0.35+0.0042H 0,5 4 17 GraniteGandes France 44 1967 1.6 1,3Piedras Spain 40 W/F 1967 1.3 1,3 0,25 0,5 4 SandstoneRama Yugoslavia 110 1967 1.3 1,3

Kangaroo Creek Australia 59 W/F 1968 1.3 1,4 0.3+0.005H 0,5 3.7 8 Schist 355 19Pindari Australia 45 I/W/F 1969 1.3 1,3 0.48+0.002H 0,81 2.6+0.085H 16 Rhyolite 623 37

Cethana Australia 110 P 1971 1.3 1,3 0.3+0.002H 0,6 3-5.36 24 Quartzite 1376 109

Oasa Romania 91 1971 1.3 1,6 0,6 0,5 Gallery 24 SchistLesu Romania 61 1973 1.3 1,3 0.3+0.007H 0,5 T 5 Rhyolite

Alto Anchicaya Colombia 140 P 1974 1.4 1,4 0.3+0.003H 0,5 7 22 Hornfeld 2400El Tejo Spain 40 1974 1.3 1,4 0,25 0,25 9 Limestone 270 1

Los Campitos Spain 54 1974 1.35 1,4 0,3 0,4 28 Basalt 576 3





Kootenay Canal Canada 37 1975 2.0 1,3 0,2 0,6 2-4 20 Gneiss 3000Rouchain France 60 1976 1.4 1,4 0.35+0.0042H 0,5 4 16 GraniteSurduc Romania 37 1976 1.5 1,5 0.4+0.005H 0,5 Trench Schist

Little Para Australia 54 W 1977 1.3 1,4 0.3+0.0029H 0,5 4 10 Shaley/dolomite 265 21Rubiales Romania 43 1977 1.4 1,4 Peridotite

Batubesi (Larona) Indonesia 30 P 1978 1.3 1,5 0,25 0,3 4 Spill way over damChuza (Gollilas) Colombia 130 W/P 1978 1.6 1,6 0.3+0.0037H 0,4 3.0 1,4 Gravel

Fantanele Romania 92 1978 1.3 1,3 0.3+0.007H 0,5 Gallery 34,2 GraniteOutades No.2 Canada 55 P 1978 1.4 1,4 0,3 0,45 3.05 8 GneissBailey, R.D. W. Vir, USA 95 F/R 1979 2.0 2.0 0,3 0,5 3.05+0.0019 65 Sandstone

Winneke/Sugarloaf Australia 85 W 1979 1.5 2.2 0.3+0.002H 0,45 0.1H 83 Sandstone 4700 100Min/6M

Areia Brazil 160 P 1980 1.4 1.4 0.3+0.0034H 0,4 4.55, 5.75 139 Basalt 13 000 6100Cerma Romania 91 1980 1.3 1.3 0.4+0.002H 0,5 Trench 5,4 LimestoneStorvas Norway 80 P 1980 1.3 1.3

Barrendiola Spain 47 1981 1.6 1.5Mackintosh Australia 75 P 1981 1.3 1.3 0,25 0,7 3.0-3.86 27 Greywacke 850 949

Mangrove Creek Australia 80 W 1981 1.5 1.6 0.375+0.003H 0,35 3, 4, 5 29 Siltstone 1340 170Mohammed B.A.K. Morocco 40 W/I 1981 1.9 2.2 0,3 0,4 23 Gravel/panelwall 650 36

Mulagua Spain 56 I 1981 1.3 1.3 212Neveri (Turimiquire) Venezuela 115 W 1981 1.4 1.5 0.3+0.002H 0,5 h3.5-v7.50 53 Limestone

Urkulu Spain 52 W 1981 350 10Aixola Spain 51 W 1982 51 1.35 1,45 375 3

Awonga Australia 47 I 1982 1.3 1.3 0.3+0.002H 0,75 Existing 30 Mata sedimentsConcrete/ Siltstone/

dam sandstoneFortuna Panama 65 P 1982 1.3 1.4 0.41+0.003H 0,5 4.0 22 Andesite

Lyell Australia 46 W 1982Murchison Australia 89 P 1982 1.3 1.3 0,3 0,65 3-4.6 16 Rhyolite 905 97alfilorios Spain 75 W 1983 1.4 1.4 Limestone 345 15

Amalahuigue Spain 60 1983 1.4 1.4Bastayan Australia 75 P 1983 1.3 1.3 0,25 0,7 3-3.8 19 Rhyolite 600 124

Boondoma No.1 Australia 63 W/I 1983 1.3 1.3 0,3 0,4 3.5-5.5 25 Rhyolite

Glennies Creek Australia 67 W/I 1983 1.3 1.3 0,3 0,43 3-4 25 Welded tuff 947 284Pecineagu Romania 105 1983 1.7 1.7 0.35+0.0065H 0,4 Gallery 30 QuartziteSalvajina Colombia 148 1983 1.5 1.4 0.3+0.0031H 0,4 4.0-8.0 50 Dredger tailings 4100

greywacke





San Anton Spain 68 1983 1.35 1.35Bejar Spain 71 I 1984 1.3 1.3 0.35+0.003H 0,4 3-H/15 19 Granite

Fortuna Raised Panama 105 1984 1.3 1.4 0,15 0,25 4.0 Andesiteshortcrete

Khao Laem Thailand 130 P 1984 1.4 1.4 0.3+0.003H 0,5 4.5(Gallery) 140 LimestoneShiroro Nigeria 130 P 1984 1.3 1.3 0.3+0.003H 0,4 6 50Alsasua Spain 50 W/I 1985 1.5 1.4 0.3+0.003H 0,4 4.5(Gallery) 14 Limestone

Batang Ai (Main) Malaysia 70 P 1985 1.4 1.4 0,3 0,5 4.6 65 Dolorite 4000 2360Bolboci Romania 56 1985 1.3 1.3 0.3+0.007H 0,4 Gallery 6 LimestoneKotmale Sri Lanka 97 P 1985 1.4 1.45 0.3+0.003H 0,65 3-8 60 Charnockite

Terror Lake Alaska 58 1985 1.5 1.4 0.3+0.003H 0,4 Greywacke

Donbog South Korea 45 1986 1.5 1.5 0.3+0.008H 0,5 5.3 7 AndesiteKekeya China 42 I 1986 1.2-2.751.5-1.75 0.3-0.5 0.0 3 12 Gravel 440 12Koman Albania 133 P 1986

Reece (L. Pieman) Australia 122 P 1986 1.3 1.3-1.5 0.3-0.001H 0,65 3-9 35 Dolerite 2700 6411Cirata Indonesia 125 P 1987 1.3 1.4 0.35+0.003H 0,4 4, 5, 7 Breccia/andesite

Corumbel Bajo Spain 46 1987 1.5 1.5Split Rock Australia 67 I 1987 1.3 1.3 0,3 0,35 Greywacke/gravel 1048 398

Ahnihg Malaysia 74 W/P 1988 1.3 1.3 0,3 0,61 6 16 Quartzite/ 700 235conglomerate

Balsam Meadows Calif, USA 40 P 1988 1.4 1.4 GraniteGuadalcacin Spain 78 1988 1.5 1.5 1098 800

Guamenshen China 59 W/F/I/P 1988 1.4 1.6 0.3+0.003H 0,5 3-5 8 Andesite 440 81Kurtun Turkey 133 P 1988 1.4 1.5 0.3+0.003H 0,4 10 58 Granodiorite 2747 108

Odeleite Portugal 61 W/I 1988 1.4 1.4 0.5+0.005H 0,5 Schist/greywacke 1000 130Spicer Meadow Calif, USA 82 P 1988 1.4 1.4 0.3+0.003H 0.4 6 Granite

Truro Peru 50 1988 1.5 1.5 0,4 0,5 3-5.0 Breccia White Spur Australia 45 P 1988 1.3 1.3 0,25 0,5 3-4.2 5 Tuff (Cambrian)Bradley Lake Alaska, USA 40 P 1989 1.6 1.6 0,3 0,5 4-5 GreywackeChengbing China 75 1989 1.3 1.3 0.3+0.0027H h0.3-v0.5 3-12 16 Tuff lava 52 8Gou Hou China 70 W/I 1989 1.6 1.55 0.3+0.004H 0.35-0.5 4-5 22 Gravel (silty) 890 3

Ulu Al Malaysia 110 P 1989 1.3 1.4 0,61 6 48 Greywacke/sandstone

Xibeikou China 95 P/I/F 1989 1.4 1.4 0.3+0.003H 0.4, 0.5 5-6 29.5 Limestone 17 935 210Alfilorios Spain 7 W 1990 1.4 1.35 0,3 Gallery Limestone 67 23

Crotty Australia 82 P 1990 1.3 1.5 0,3 0,5 3-4.2 13 Gravel quartzite/ 784 1060dolerite spillway

over dam





Long Xl China 59 I/F/H 1990 1.3 1.3 0,4 h0.3-v0.5 3-5 7 Tuff lava 260 16Luocun China 58 I 1990 1.2 1.2-1.4 0,3 0.4-0.5 5-6 12 Dumped rock/ 640 21

sandstoneShushuqiao China 78 I/F/H 1990 1.4 1.7 0.3+0.003H 0,35 3.5-5.0 28 Limestone/slate 720 278

Xiaogan Gou China 55 P 1990 1.55 1.6 0,3 0,55 3.5-4.5 5 Gravel 240 10Ibag-Eder Spain 65 W 1991 750 11,3

Bejar Spain 71 W 1992 1.3 1.3 3-H/15 19 Granite 763 14Doulanggou China 35 I 1992 7 Limestone 100 4

Guangzhou Upper China 68 P 1992 1.4 1.4 0.3+0.003H 0,4 19 Granite 800 17Hengshan (raised) China 70 W/I/P 1992 1.4 1.3 0,3 0,4 4 10 Tuff lava 1090 112

Segredo Brazil 145 P 1992 1.3 1.2-1.4 0.3+0.0035H 0.3, 0.4 4-6.5 86 Basalt 6700 3000

Tongjiezi Saddle China 48 P 1992 2.5-3 15 Gravel, basalt 700 200Aguamilpa Mexico 187 P 1993 1.5 1.4 0.3+0.003H 0.3-0.35 137 Graval/ignimbrite 4000 6950Anthony Australia 47 P 1993 1.3 1.3 3-4 4 110 39Huashan China 81 P 1993 1.4 1.4 h0.4-v0.5 h0.4-v0.5 3-6 13 Granite 700 63

Baiyanghe China 37 I 1994 Gravel 370 6Chase Gulch Colorado, USA 40 W 1994

Fortuna (Raised) Panama 105 P 1994 1.3 1.4 0,15 0,25 4 AndesitePindari (Raised) Australia 83 I/F 1994 1.3 1.3 0,3 0,3 4 Rhyolite 2695 312

Shewang China 36 W 1994 1.3 1.3 0,15 4 7 Tuff 120 3Shisanling (Upper) China 75 P 1994 1.5 1.7 0,3 0.5, 0.6 32 Andesite 2700 4

Limestone

Siah Bishe (Upper) Iran 100 P 1994 1.5 1.6 Dolomite,Siah Bishe (Lower) Iran 130 P 1994 1.5 1.6 Limestone, basalt

Xiaomeisha China 49 S 1994 0,35 6 220 146Xingo Brazil 150 P 1994 1.4 1.3 0.3+0.0029H 0,4 5-7 135 Granite gneiss 12 300 3800

Dongjin China 86 S/P/I 1995 1.4 1.3 0.3+0.0023H 0,4 4-8 28 sandstone 1760 800Jaraiz de la Vera Spain 46 S 1995

Messochora Greece 135 P/I 1995 1.4 1.4 0.3+0.003H 0,5 0.7 50 LimestoneNamgang Korea 34 1995 1.3 1.3 0,35

Pichi-Pic un-leufu Argentina 40 P 1995 1.5 1.5 0,3 0,35 4 Gravel, panel wallRoseau Santa Lucia 40 W 1995 1.3 1.5 0,3 0,33 3.3 6.8 Andesite

Santa Juana Chile 110 W/I 1995 1.5 1.6 0.3+0.002H 0,3 3-5 Gravel, panel wall 390 160Wananxi China 94 P 1995 1.4 1.4 0.3+0.0037H 0,5 5-6 21 Granite, porphry 1290 228Babagon Malaysia 63 W 1996 1.3 1.6 0,3 3-5 sandstone, randomBaiyibuxi China 35 I 1996 GravelBaiyun China 120 P 1996 1.4 1.4 0.3+0.002H h.35, v.4 4-5 15 Limestone 1700 360





Douyan China 58 1996 1.4 1.6 18 Granite 120 98Haichaba China 57 I 1996 1.4 1.3-1.4 0,35 h0.4-v0.5 4-5 13 Granite 48 8Houay Ho Loas 85 P 1996 1.4 1.5 0,3 0,52 4-9 22 Sandstone 1250 595Nanche China 64 1996 1.4 1.4 Sandstone 460 153Pingtan China 55 I/S 1996 290 11

Suojinshan China 62 1996Xixou China 35 P 1996

Yacambu Venezuela 162 W 1996 1.5 1.6 0.3+0.002H 0,4 Concrete 13 Gravel 435dam

Zhalong China 39 I 1996 9 Gravel 370 138Bastonia Romania 110 1997 1.5 1.5 0.3+0.003H 0,5 4.6 30 Andesite

Chakoukane Morocco 63 I 1997 1.6 1.6 Gravel panelwall 1800 50Dahe China 68 P/F 1997 1.5 1.4 0,4 Limestone, slate 900 332

Francis Creek Australia I 1997 1.3 1.3 0,3 3-5 Spillway overcrestGudongkou China 120 I/F/P 1997 1.4 1.5 0.3+0.003H h.4, v.5 4.5-10 Gravel, limestone 1900 138Kalangguer China 61 P/F/S/I 1997 1.5 1.4 0.3+0.003H h.4, v.5 4-5-6 36 Gravel, sandstone 1200 39Liangchahe China 43 I/F/P 1997 1.5 1.6 0,3 5 Gravel 510 63

Lianhua China 72 1997 1.4 1.4 7.5 52 Granite 4230 4180Meixi China 38 I 1997

Poneasca Romania 52 1997 1.3 1.4 0.3+0.001H 0,5 2.5 5.2 LimestoneRastolnita Romania 110 1997 1.5 1.5 0.3+0.003H 0,5 4.0-6.0 30 Andesite

Shankou China 39 H/I 1997 1.4 1.4 0,3 0,4 3 Tuff 650 46Shedong China 50 1997

Tasite China 43 I 1997 450 12Tianhuangping China 95 P 1997 1.4 1.3 0.3+0.002H 0,4 4-6 21 Rhyolite, tuff lava 1420 9

Badu China 58 I/S/F/P 1998 1.3 1.3 Tuff, lava 840 377Liangjiang China 55 1998 1110 210Songshan China 79 P 1998 1.4 1.4 0.3+0.003H 0,5 6-8 24 Andesite 1420 123

Tianshenggiao China 180 P/I/F 1998 1.4 1.4 0.3+0.005H 0,4 4-9 168 Limestone 17 690 18 260Wuluwadi China 138 F/I/P 1998 1.6 1.6 0.3+0.003H h.4, v.5 6-10 76 Gravel, schist 6800 340Xiadshan China 86 1998 1.4 1.4 0.3+0.003H 6-8 36 Andesite, basalt 1430

Xiaoxikou China 72 I/P 1998 Limestone 1110 66Yubeishan China 72 1998

Zeya China 79 S/F/P 1998 Tuff, lava 1420 57



Sheet2



Caruachi Venezuela 80 P 1999 1,3 1,3 0,35 0,35 3 60 Granite, Gneiss 2000 4

Chaishitan China 102 I/H 1999 1,4 1,4 0.3+0.003H 6-7 38 Dolomite 2170 437

Daiqiad China 91 S/I/P 1999 1.5 1.7 0.3-0.5 0.3 2090 158

Dauo China 90 1999 Sandstone 1450 278

Gaotang China 111 1999 Granite 1950 96

Heiguan China 124 S/I/F/P 1999 1.55 1.4 0.3+0.0035H 0.3, 0.4 4-7 79 Gravel, Granite 550 182Gneiss

Ita Brazil 125 P 1999 1.3 1.3 0.3+0.002H 0.3H 0.4V 4-6 110 Basalt 9300 5100

Qjezishan China 104 I/P 1999 1.4 1.4 0.3+0.003H 0.3 0.4 5-7 Granite 1400 121

Runcv Romania 90 1999 1.4 1.4 0.3+0.002H 0.45 4.0 26.2 Granite

Sanchaxi China 89 1999 14 720 47

Sanguozhuang China 63 I/P 1999 20 Basalt 800

Atasu Turkey 118 2000

Hongzhuhe China 52 I/P 2000

Kurtun Turkey 133 P 2000 1.4 1.5 0.3+0.003H 0.4 10 58 Granodorite 2747 108

Mohale Lesotho 145 I/P 2000 1.4 1.4 0.3+0.0035H 0.4 3+H/15 87 Basalt 7400 938

Pim Turkey 135 I/P/W 2000

Puclaro Chile 100 I 2000 1.5 1.5 0.3

Yang Yang Korea 93 P 2000 1.4 1.4 0.35 5 Gneiss

Yedigaze Turkey 105 2000

Dchar El Qued Morocco 101 I 2001 Gravel

Guasquitas Panama 49 P 2001 1.4 1.5 0.3 0.3 3 Gravel



Mukorsi Zimbabwe 90 I 2001

Nam Ngum 3 Laos 220 P 2001 1.4 1.4 0.3+0.003H 0.3, 0.11 4-11 5 Sandstone,limestone

Sogamoso Colombia 190 P 2001 1.4 1.4 0.3+0.002H 0.3 0.4 6-10 75 Gravel

Gordes Turkey 87 I/W

Kwai Nai-Main Thailand 95 I 2002 1.4 1.4

La Regadera II Colombia 120 W 2002 1.5 1.6 0.3+0.002H 0.3H 0.35V 3 Gravel

Torata Peru 100 W 2002 1.3 1.3 0.3+0.002H 0.3H 0.35V 4

Dhauliganga India 50 H 2003 GneissPanel cut off

Cercado Colombia 120 2003 1.4 1.4 0.3+0.002H 0.35H 0.4V 3-6 37 Vulcanite 2900 198

Itatebi Brazil 100 2003 1.3 1.3 0.42 0.35H 0.4V 3-5 70 Gneiss, Diorite 3100 1650

Mazar Equardor 171 P 2003

Tocoma Venezuela 40 P 2004 1.3 1.3 0.35 0.3H 0.35V 3 Gneiss

Acena Spain 65 I UD 1.3 1.3 0.3+0.003H 0.4 3+H/15 Gneiss

Antamina Peru 115 Tailings UD 1.3 1.3 0.3 0.35 4 Limestone2nd Stage 200 1.3 1.4 mine tailings dam

Agbulu Philippines 234 P UD 1.4 1.5 21 000 3981

Arriaran Spain 50 UD 1.4 1.4

Baixi China 124 UD 1.4 1.4 Tuff, lava, 3700 164Sandstone

Bakun Malaysia 205 P UD 1.4 1.4 0.3+0.003H 0.3 0.4 4-6 127 Greywacke, 17 000 43 800

Page 1



Sheet2

siltstone

Boaina Brazil 80 P UD 1.3



Canvelo Spain 35 UD

Carcauz Spain 70 UD

Corrales Chile I UD Gravel

Daliushu China 164 I/P UD 1.6 1.6-1.8 0.3+0.003H 0.35 6-10 17 Sandstone 14 500

Diguillin Chile I UD

Gongbaixia China 127 UD 1.4 1.4 0.3+0.003H 0.4 4-8 160 Granite, Gravel 4550 550

Hon Gjiadu China 187 P UD 1.4 1.4 0.3+0.003H 0.5 6-10 156 Limestone 10 070 4540Sandstone

Ibba Yeder Spain 66 UD 1.35 1.5

Jiemlan China 126 P/I/F UD Sandstone, 3420 1085mudstone

Jilingtai China 157 P UD 1.5 1.9 0.3+0.003H 0.5, 0.4 6-10 74 Tuff 9200 2440

Jilintai Laos 152 UD 1.5 1.5 74 Tuff

Jishixia China 100 P UD 1.5 1.55 0.3+0.003H 0.4, 0.5 4, 6, 7.4 29 Gravel, ballast 2880 263

Kaliwa Philippines 100 UD

Pankou China 123 P UD 1.4 1.5 0.3+0.0038H 0.5 4-7.5 46 Limestone 3460 2460

Panshitou China 106 S/F/I/P UD 1.4 1.5 0.3-0.5 0.3, 0.4 75 Sandstone, shale 1510 679

Qinshan China 122 UD 42 Tuff 3100 265

San Banxi China 186 P UD 1.4 1.4 0.3+0.0035H 0.4 6-12 94 Sandstone 960 4170

Sancheng 1 Korea 65 P UD 1.4 1.4 0.3+0.002H


Santarita Brazil 85 P UD 1.3 1.3

Shanxi China 129 UD 1.4 1.4 0.3+0.003H 0.4 6-10 61 Rhyolite, gravel 5000 1922 Rockfill Reservoir

Name Country Height Purpose Year Slope Face slab t Reinforcing Plinth Face area Type Volume capacitym Completed US DS =m+CH each way width, m 10^3 m^3 10^3 m^3 10^3 m^3

Shuanggu China 110 P UD 1.4 1.4 0.3+0.003H H.3, V.4 3.5 41 Andesite, basalt 2580 391

Shui Bu Ya China 232 P UD 1.4 1.4 0.3+0.003H 0.4 4-10 Limestone 15 500 4700

Taia Romania 64 UD 1.65 1.55 Gallery 9.7 Schist

Tankeng China 161 UD 1.4 1.4 0.3+0.003H 0.4 6-10 94 Welded tuff 10 000 3530

Taoshui China 103 UD 1.4 1.55 29 1720 52

Wa Wushan China 140 I/P UD 545

Yesa Spain 117 I/P UD 1.3 1.5

Yutiao China 110 S/P/I UD 1.4 1.5 Sandstone 1630 95

Zipingpau China 159 UD 1.4 1.5 127 Sandstone 11 670 1080

Awonga Raised Australia 63 Z

Babaquara Brazil 80 P Z 1.3 1.3 0.3

Bajiaotan China 70 Z 1.4 1.4 Shale

Barra Grande Brazil 170 P Z

Boon. Stage 2 Australia 73 Z

Campos Novos Brazil 210 P Z

Cirata (Raised) Indonesia 140 P Z

Cuesta Blanca Argentina 80 Z 1.4 1.5 0.3+0.003H

Guizhou Horgjiadu China 182 P Z Limestone

Page 2



Sheet2

Huallaga Peru 140 Z

Huangliao China 40 Z 1.4 1.4 0.25 0.35 3 2 Tuff, lavaSpillway over dam

Irape Brazil 190 P Z



Jurua Brazil 40 P Z 1.3 1.3 0.25

Kaeng Krung Thailand 110 P/I Z 1.3 1.3-1.5 0.3

Laredo Spain 40 Z 1.3 1.5

Los Molles Argentina 46 Z 1.5 1.5 0.3+0.003H 6 12 Gravel 730 20 000panel wall

Man.Cr.Raised Australia 105 W Z 1.5 1.6 0.3+0.003H 0.35 3, 4, 5 34 Siltstone/sandstone

M'dez Morocco 97 I/P Z 1.8 1.6 0.3+0.003H 0.3 3-5 40 Gravel 1900 600spillway over dam

Merowe (Nile) Sudan 83 P Z 1.3 1.4 0.3+0.003H 0.3, 0.4 4-15 Granite

Murum Malaysia 141 P Z 1.4 1.4 0.3+0.003H 0.35 3-15 74 Greywacke, 6600 12 043mudstone

Nam Khek Thailand 125 P/I Z 1.4 1.5 0.4 4-7 59 Conglomerate,sandstone

Pipay-Guazu 2 Argentina 73 Z 1.3 1.3 0.3+0.004H

Porce III Colombia 145 P Z

Quimbo Colombia 150 P Z 1.5,1.6 Gravel

Tetelcingo Mexico 150 P Z 1.5 1.5 0.3+0.002H

West Seti Nepal 220 P Z 1.5 1.6 0.3+0.003H 0.4 4-11 Gravel 12 500 1604

Xe Kaman Laos 187 P Z 1.3 1.3 0.3+0.002H 0.35H 0.4V 4-9 84 Sandstone 9200 17 330

El Cajon Mexico 189 P C 1.5 1.4 0.3+0.003H 99 Gravel, 10 000 2368ignimbrite

La Parota Mexico 162 P C 1.5 1.4 0.3+0.003H 4-8 170 Gravel, gneiss 12 000 6752

Lungga Solomons

Ta Seng Myanmar 162 P C Rockfill Reservoir


Xe Namnoy Laos 78 P C

Al Wehda (Stage 1) Jordan 140 W/I Delayed 1.3 1.5 0.3+0.003H 0.5 Basalt

Al Wehda (Stage 2) Jordan 190 1.3 1.5

Page 3



Sheet2.1



Caruachi Venezuela 80 P 1999 1,3 1,3 0,35 0,35 3 60 Granite, Gneiss 2000 4Chaishitan China 102 I/H 1999 1,4 1,4 0.3+0.003H 6-7 38 Dolomite 2170 437

Daiqiad China 91 S/I/P 1999 1.5 1.7 0.3-0.5 0.3 2090 158Dauo China 90 1999 Sandstone 1450 278

Gaotang China 111 1999 Granite 1950 96Heiguan China 124 S/I/F/P 1999 1.55 1.4 0.3+0.0035H 0.3, 0.4 4-7 79 Gravel, Granite 550 182

GneissIta Brazil 125 P 1999 1.3 1.3 0.3+0.002H 0.3H 0.4V 4-6 110 Basalt 9300 5100

Qjezishan China 104 I/P 1999 1.4 1.4 0.3+0.003H 0.3 0.4 5-7 Granite 1400 121Runcv Romania 90 1999 1.4 1.4 0.3+0.002H 0.45 4.0 26.2 Granite

Sanchaxi China 89 1999 14 720 47

Sanguozhuang China 63 I/P 1999 20 Basalt 800Atasu Turkey 118 2000

Hongzhuhe China 52 I/P 2000Kurtun Turkey 133 P 2000 1.4 1.5 0.3+0.003H 0.4 10 58 Granodorite 2747 108Mohale Lesotho 145 I/P 2000 1.4 1.4 0.3+0.0035H 0.4 3+H/15 87 Basalt 7400 938

Pim Turkey 135 I/P/W 2000Puclaro Chile 100 I 2000 1.5 1.5 0.3

Yang Yang Korea 93 P 2000 1.4 1.4 0.35 5 GneissYedigaze Turkey 105 2000

Dchar El Qued Morocco 101 I 2001 Gravel

Guasquitas Panama 49 P 2001 1.4 1.5 0.3 0.3 3 GravelMukorsi Zimbabwe 90 I 2001

Nam Ngum 3 Laos 220 P 2001 1.4 1.4 0.3+0.003H 0.3, 0.11 4-11 5 Sandstone,Sogamoso Colombia 190 P 2001 1.4 1.4 0.3+0.002H 0.3 0.4 6-10 75 Gravel

Gordes Turkey 87 I/WKwai Nai-Main Thailand 95 I 2002 1.4 1.4La Regadera II Colombia 120 W 2002 1.5 1.6 0.3+0.002H 0.3H 0.35V 3 Gravel

Torata Peru 100 W 2002 1.3 1.3 0.3+0.002H 0.3H 0.35V 4

Dhauliganga India 50 H 2003 GneissPanel cut off

Cercado Colombia 120 2003 1.4 1.4 0.3+0.002H 0.35H 0.4V 3-6 37 Vulcanite 2900 198

Itatebi Brazil 100 2003 1.3 1.3 0.42 0.35H 0.4V 3-5 70 Gneiss, Diorite 3100 1650

Mazar Equardor 171 P 2003

Tocoma Venezuela 40 P 2004 1.3 1.3 0.35 0.3H 0.35V 3 Gneiss

Acena Spain 65 I UD 1.3 1.3 0.3+0.003H 0.4 3+H/15 Gneiss

Antamina Peru 115 Tailings UD 1.3 1.3 0.3 0.35 4 Limestone2nd Stage 200 1.3 1.4 mine tailings dam

Agbulu Philippines 234 P UD 1.4 1.5 21 000 3981

Arriaran Spain 50 UD 1.4 1.4

Baixi China 124 UD 1.4 1.4 Tuff, lava, 3700 164Sandstone

Bakun Malaysia 205 P UD 1.4 1.4 0.3+0.003H 0.3 0.4 4-6 127 Greywacke, 17 000 43 800siltstone

Boaina Brazil 80 P UD 1.3



Canvelo Spain 35 UD

Carcauz Spain 70 UD

Corrales Chile I UD Gravel

Daliushu China 164 I/P UD 1.6 1.6-1.8 0.3+0.003H 0.35 6-10 17 Sandstone 14 500

Diguillin Chile I UD

Gongbaixia China 127 UD 1.4 1.4 0.3+0.003H 0.4 4-8 160 Granite, Gravel 4550 550

Hon Gjiadu China 187 P UD 1.4 1.4 0.3+0.003H 0.5 6-10 156 Limestone 10 070 4540

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Sandstone

Ibba Yeder Spain 66 UD 1.35 1.5

Jiemlan China 126 P/I/F UD Sandstone, 3420 1085mudstone

Jilingtai China 157 P UD 1.5 1.9 0.3+0.003H 0.5, 0.4 6-10 74 Tuff 9200 2440

Jilintai Laos 152 UD 1.5 1.5 74 Tuff

Jishixia China 100 P UD 1.5 1.55 0.3+0.003H 0.4, 0.5 4, 6, 7.4 29 Gravel, ballast 2880 263

Kaliwa Philippines 100 UD

Pankou China 123 P UD 1.4 1.5 0.3+0.0038H 0.5 4-7.5 46 Limestone 3460 2460

Panshitou China 106 S/F/I/P UD 1.4 1.5 0.3-0.5 0.3, 0.4 75 Sandstone, shale 1510 679

Qinshan China 122 UD 42 Tuff 3100 265

San Banxi China 186 P UD 1.4 1.4 0.3+0.0035H 0.4 6-12 94 Sandstone 960 4170



Santarita Brazil 85 P UD 1.3 1.3

Shanxi China 129 UD 1.4 1.4 0.3+0.003H 0.4 6-10 61 Rhyolite, gravel 5000 1922 Rockfill Reservoir


Shuanggu China 110 P UD 1.4 1.4 0.3+0.003H H.3, V.4 3.5 41 Andesite, basalt 2580 391

Shui Bu Ya China 232 P UD 1.4 1.4 0.3+0.003H 0.4 4-10 Limestone 15 500 4700

Taia Romania 64 UD 1.65 1.55 Gallery 9.7 Schist

Tankeng China 161 UD 1.4 1.4 0.3+0.003H 0.4 6-10 94 Welded tuff 10 000 3530

Taoshui China 103 UD 1.4 1.55 29 1720 52

Wa Wushan China 140 I/P UD 545

Yesa Spain 117 I/P UD 1.3 1.5

Yutiao China 110 S/P/I UD 1.4 1.5 Sandstone 1630 95

Zipingpau China 159 UD 1.4 1.5 127 Sandstone 11 670 1080

Awonga Raised Australia 63 Z

Babaquara Brazil 80 P Z 1.3 1.3 0.3

Bajiaotan China 70 Z 1.4 1.4 Shale


Boon. Stage 2 Australia 73 Z

Campos Novos Brazil 210 P Z

Cirata (Raised) Indonesia 140 P Z

Cuesta Blanca Argentina 80 Z 1.4 1.5 0.3+0.003H


Huallaga Peru 140 Z

Huangliao China 40 Z 1.4 1.4 0.25 0.35 3 2 Tuff, lavaSpillway over dam

Irape Brazil 190 P Z



Page 2



Sheet2.1

Jurua Brazil 40 P Z 1.3 1.3 0.25



Los Molles Argentina 46 Z 1.5 1.5 0.3+0.003H 6 12 Gravel 730 20 000panel wall

Man.Cr.Raised Australia 105 W Z 1.5 1.6 0.3+0.003H 0.35 3, 4, 5 34 Siltstone/sandstone

M'dez Morocco 97 I/P Z 1.8 1.6 0.3+0.003H 0.3 3-5 40 Gravel 1900 600spillway over dam

Merowe (Nile) Sudan 83 P Z 1.3 1.4 0.3+0.003H 0.3, 0.4 4-15 Granite

Murum Malaysia 141 P Z 1.4 1.4 0.3+0.003H 0.35 3-15 74 Greywacke, 6600 12 043mudstone

Nam Khek Thailand 125 P/I Z 1.4 1.5 0.4 4-7 59 Conglomerate,sandstone

Pipay-Guazu 2 Argentina 73 Z 1.3 1.3 0.3+0.004H

Porce III Colombia 145 P Z

Quimbo Colombia 150 P Z 1.5,1.6 Gravel


West Seti Nepal 220 P Z 1.5 1.6 0.3+0.003H 0.4 4-11 Gravel 12 500 1604

Xe Kaman Laos 187 P Z 1.3 1.3 0.3+0.002H 0.35H 0.4V 4-9 84 Sandstone 9200 17 330


La Parota Mexico 162 P C 1.5 1.4 0.3+0.003H 4-8 170 Gravel, gneiss 12 000 6752

Lungga Solomons

Ta Seng Myanmar 162 P C Rockfill Reservoir


Xe Namnoy Laos 78 P C

Al Wehda (Stage 1) Jordan 140 W/I Delayed 1.3 1.5 0.3+0.003H 0.5 Basalt

Al Wehda (Stage 2) Jordan 190 1.3 1.5

Page 3



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Page 4



Sheet3.1

Bastonia ? 110 1997 1.5 1.5 0.3+0.003H 0,5 4.6 30 AndesiteTerror Lake Alaska 58 1985 1.5 1.4 0.3+0.003H 0,4 Greywacke

Bradley Lake Alaska, USA 40 P 1989 1.6 1.6 0,3 0,5 4-5 GreywackeKoman Albania 133 P 1986

Cuesta Blanca Argentina 80 Z 1.4 1.5 0.3+0.003HLos Molles Argentina 46 Z 1.5 1.5 0.3+0.003H 6 12 Gravel 730 20 000

Pichi-Pic un-leufu Argentina 40 P 1995 1.5 1.5 0,3 0,35 4 Gravel, panel wallPipay-Guazu 2 Argentina 73 Z 1.3 1.3 0.3+0.004H

White Spur Australia 45 P 1988 1.3 1.3 0,25 0,5 3-4.2 5 Tuff (Cambrian)Anthony Australia 47 P 1993 1.3 1.3 3-4 4 110 39Awonga Australia 47 I 1982 1.3 1.3 0.3+0.002H 0,75 Existing 30 Mata sediments

Awonga Raised Australia 63 ZBastayan Australia 75 P 1983 1.3 1.3 0,25 0,7 3-3.8 19 Rhyolite 600 124

Boon. Stage 2 Australia 73 ZBoondoma No.1 Australia 63 W/I 1983 1.3 1.3 0,3 0,4 3.5-5.5 25 Rhyolite

Cethana Australia 110 P 1971 1.3 1,3 0.3+0.002H 0,6 3-5.36 24 Quartzite 1376 109Crotty Australia 82 P 1990 1.3 1.5 0,3 0,5 3-4.2 13 Gravel quartzite/ 784 1060

Francis Creek Australia I 1997 1.3 1.3 0,3 3-5 Spillway overcrestGlennies Creek Australia 67 W/I 1983 1.3 1.3 0,3 0,43 3-4 25 Welded tuff 947 284Kangaroo Creek Australia 59 W/F 1968 1.3 1,4 0.3+0.005H 0,5 3.7 8 Schist 355 19

Little Para Australia 54 W 1977 1.3 1,4 0.3+0.0029H 0,5 4 10 Shaley/dolomite 265 21Lyell Australia 46 W 1982

Mackintosh Australia 75 P 1981 1.3 1.3 0,25 0,7 3.0-3.86 27 Greywacke 850 949Man.Cr.Raised Australia 105 W Z 1.5 1.6 0.3+0.003H 0.35 3, 4, 5 34 Siltstone/

Mangrove Creek Australia 80 W 1981 1.5 1.6 0.375+0.003H 0,35 3, 4, 5 29 Siltstone 1340 170Murchison Australia 89 P 1982 1.3 1.3 0,3 0,65 3-4.6 16 Rhyolite 905 97

Pindari Australia 45 I/W/F 1969 1.3 1,3 0.48+0.002H 0,81 2.6+0.085H 16 Rhyolite 623 37Pindari (Raised) Australia 83 I/F 1994 1.3 1.3 0,3 0,3 4 Rhyolite 2695 312

Reece (L. Pieman) Australia 122 P 1986 1.3 1.3-1.5 0.3-0.001H 0,65 3-9 35 Dolerite 2700 6411Split Rock Australia 67 I 1987 1.3 1.3 0,3 0,35 Greywacke/gravel 1048 398

Winneke/Sugarloaf Australia 85 W 1979 1.5 2.2 0.3+0.002H 0,45 0.1H 83 Sandstone 4700 100Areia Brazil 160 P 1980 1.4 1.4 0.3+0.0034H 0,4 4.55, 5.75 139 Basalt 13 000 6100

Babaquara Brazil 80 P Z 1.3 1.3 0.3Barra Grande Brazil 170 P Z

Bocaina Brazil 80 P UD 1.3Campos Novos Brazil 210 P Z

Ita Brazil 125 P 1999 1.3 1.3 0.3+0.0025H 0.3H 0.4V 4-6 110 Basalt 9300 5100Itatebi Brazil 100 2003 1.3 1.3 0.42 0.35H 0.4V 3-5 70 Gneiss, Diorite 3100 1650Jurua Brazil 40 P Z 1.3 1.3 0.25

Machadinho Brazil 125 P 2002 1.3 1.3 0.3+0.0033H 0.3 3-6 93 Sandstone 6800Santa Rita Brazil 85 P UD 1.3 1.3Segredo Brazil 145 P 1992 1.3 1.2-1.4 0.3+0.0035H 0.3, 0.4 4-6.5 86 Basalt 6700 3000

Xingo Brazil 150 P 1994 1.4 1.3 0.3+0.0029H 0,4 5-7 135 Granite gneiss 12 300 3800Balsam Meadows Calif, USA 40 P 1988 1.4 1.4 Granite

Cogswell Calif, USA 85 F 1934 1,35 1,6 0,3 T DR-granite 799 13Courtright Calif, USA 98 P/I 1958 1.0-1.3 1,3 0.3+0.0067H 0,5 T DR-granite 1193 152

Lower Bear No.1 Calif, USA 71 P 1952 1,3 1,4 0.3+0.0067H 0,5 T 6 DR-gravel 1002 6,4Lower Bear No.2 Calif, USA 50 P 1952 1.0 1,4 0.3+0.0067H 0,5 T 3 DR-granite

Morena Calif, USA 54 W 1895 0.5-0.9 1,3 0.23+0.003H 0,5 T DR-granite 256 61New Exchequer Calif, USA 150 P/W/I 1966 1.4 1,4 0.3+0.0067H 0,5 3-4 DR & CR- 3952 1265

Salt Springs Calif, USA 100 P/W 1931 1.1-1.4 1,4 0.3+0.0067H 0,5 T 11 DR-granite 2294 171Spicer Meadow Calif, USA 82 P 1988 1.4 1.4 0.3+0.003H 0.4 6 Granite

Strawberry Calif, USA 50 P/W 1916 1.1-1.2 1,3 0.23+0.003H 0,5 T DR-granite 1343 229Wishon Calif, USA 82 P/I 1958 1.0-1.3 1,4 0.3+0.0067H 0,5 T DR-granite 2829 158

Kootenay Canal Canada 37 1975 2.0 1,3 0,2 0,6 2-4 20 Gneiss 3000La Joie Canada 67 P 1955 1.1 1,5 Shotcrete T DR

Outardes No.2 Canada 55 P 1978 1.4 1,4 0,3 0,45 3.05 8 GneissCogoti Chile 75 I 1939 1,6 1,8 0.2+0.008H T 16 DR-gravel

Corrales Chile 70 I 2000 1.5 1.6 0.3-0.5 0.4 3-4 29 Gravel 1600 50Diguillin Chile I UDPuclaro Chile 100 I 2000 1.5 1.6 0.3-0.45 0.3 3-4 87 Gravel 4780 200

Santa Juana Chile 110 W/I 1995 1.5 1.6 0.3+0.002H 0,3 3-5 Gravel, panel wall 390 160Badu China 58 I/W/F/P 1997 1.3 1.3 6 Tuff lava 840 32Baixi China 124 W/I/P UC 1.4 1.4 0.3+0.003H 0.4 5-8 48 Tuff lava 3600 168

Baiyanghe China 37 I 1994 1.7 1.5 0.3+0.003H 0,5 2, 2.8, 3.8 21 Gravel 370 6Baiyun China 120 P 1998 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 15 Limestone, 1700 360

Bajiaotan China 70 Z 1.4 1.4 ShaleBakun China 124 W/I/F/P UC 1.55 1.4 0.3+0.0035H 0.3, 0.4 4-7 79 Gravel, Granite 5500 182

Bayibuxie China 35 I UC Gravel 200 4Caoyutan China 16 I/P 1995 1.6 1.5 0,3 h0.3, v0.5 1.5 12 Gravel 27Cengang China 28 W/I 1998 1.4 1.4 0,35 0,4 3 11 Panel wall, tuff lava 310 6

Centianhe raised China 110 P UD 2500 1600Chaishitan China 103 I/P UC 1,4 1,4 0.3+0.003H 6-7 38 Dolomite 2170 437Chalong China 39 I 1996 1.8 1.8 0,4 0,45 3-4 9 Gravel 370 138

Chengbing China 75 P 1989 1.3 1.3 0.3+0.0027H h 0.3, v 0.5 3-12 16 Tuff lava 800 52Chusong China 40 P/I UC 1.8 1.3 0.3 0.4 Gravel 700 15

Daao China 90 UC 1.4 1.4 0.3-0.6 26 Sandstone 1450 278Dahe China 68 P/F UC 1.4 1.4 0,4 3-5 Limestone, slate 900 332

Daiqiad China 91 S/I/P 1999 1.5 1.7 0.3-0.5 0.3 2090 158Daliushu China 156 I/P UD 1.6 1.8 0.3-0.8 0.35 6-10 164 Sandstone 14 500 10 743Daqiao China 91 W/I/P UC 1.5 1.7 0.3-0.5 0.3 6-9 30 Gravel 2090 658Dongjin China 89 W/P/I 1995 1.4 1.3 0.3+0.0023H 0,4 4-8 28 sandstone 1760 800

Doulanggou China 35 I 1992 7 Limestone 100 3,5Douling China 89 P/I/W/F UC 1.4 1.6 32 Limestone, Phylite 2240 485Douyan China 58 P 1996 1.4 1.6 0,3 h0.34, v0.52 4-5 19 Granite 520 98Gaotang China 111 P UC 26 Granite 1950 96

Gongbaixia China 130 P UD 1.4 1.4 0.3+0.003H 0.4 4-8 46 Granite, Gravel 4550 550Gouhou China 70 W/I 1989 1.6 1.55 0.3+0.004H 0.35-0.5 4-5 22 Gravel (silty) 890 3

Guamenshan China 59 W/F/I/P 1988 1.4 1.3 0.3+0.003H 0,38 3-5 8 Andesite 440 81Guangzhou Upper China 68 P 1992 1.4 1.4 0.3+0.003H 0,4 3-6 18 Granite 800 17

Gudongkou China 120 I/F/P UC 1.4 1.5 0.3+0.003H h 0.4, v 0.5 4.5-10 Gravel, limestone 1900 138Guizhou Horgjiadu China 182 P Z Limestone

Haichaoba China 57 I 1996 1.4 1.3-1.4 0,35 h 0.4, v 0.5 4-5 13 Granite 480 7

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Hengshan (raised) China 70 W/I/P 1992 1.4 1.3 0,3 0,4 4.4 10 Tuff lava, panel wall 1090 112Hongjiadu China 182 P UD 1.4 1.4 0.3+0.003H 0.5 6-10 76 Limestone 10 000 4590Huangliao China 40 Z 1.4 1.4 0.25 0.35 3 2 Tuff lavaHuashan China 81 P 1993 1.4 1.4 0.3+0.003H h 0.4, v 0.5 3-6 13 Granite 700 63Jiemian China 126 P/I/F UD 58 Sandstone, 3420 1058Jilingtai China 152 P UD 1.5 1.9 0.3+0.003H 0.5, 0.4 6-10 74 Tuff 9200 2440Jishixia China 100 P UD 1.5 1.55 0.3+0.003H 0.4, 0.5 4, 6, 7.4 Gravel, ballast 2880 264

Kalangguer China 62 P/F/W/I UC 1.5 1.4 0.3+0.003H h 0.4, v 0.5 5-6 36 Gravel, Andesite 1200 39Kekeya China 42 I 1982 1.2-2.75 1.5-1.75 0.3-0.5 0.0 3 12 Gravel, panel wall 440 12

Liangchahe China 43 I/F/P 1998 1.5 1.6 0,3 0.35-0.4 4-5 17 Gravel 510 63Lianghui China 35 W/I/F/P 1997 1.4 1.4 0,35 0,8 3.5-4.5 22 Panel wall, gravel 680 31Liangjiao China 55 UC 21 Granite 1110 210Lianhua China 72 P/F/I 1997 1.4 1.4 0.3+0.003H h 0.4, v 0.5 4-6 75 Granite 4230 4180Longxi China 59 I/F/H 1990 1.3 1.3 0,4 h 0.3, v 0.5 3-5 7 Tuff lava 300 26Luocun China 58 I 1990 1.2 1.2-1.4 0,3 0.4-0.5 5-6 12 Dumped rock/ 640 21Meixi China 38 I 1997 1.4 1.3 0,35 0,4 Panel wall 37 Panel wall, gravel 1200 265

Motuola China 36 UCNanche China 64 I/P/F 1996 1.4 1.4 0.3-0.45 0,425 3.5-5.5 12 Sandstone 460 153Pankou China 123 P UD 1.4 1.5 0.3+0.0038H 0.5 4-7.5 46 Limestone 3460 2460

Panshitou China 101 W/F/I/P UD 1.4 1.5 0.3-0.5 0.3, 0.4 75 Sandstone, shale 5290 679Pingtan China 55 I/S 1996 390 11

Qiezishan China 107 I/P UC 1.4 1.4 0.3+0.003H 0.3, 0.4 5-7 Granite 1400 121Qinshan China 122 P UC 1.4 1.35 0.3+0.003H 0,5 5, 6, 8 42 Tuff 3100 265Sanbanxi China 179 P UD 1.4 1.4 0.3+0.0035H 0.4 6-12 94 Sandstone 960 4170Sanchaxi China 89 UC 14 770 47

Sanguozhuang China 64 I/P/F UC 20 Basalt 800 15Shankou China 39 P/I 1996 1.4 1.4 0,3 0,4 3 9 Tuff 650 46Shanxi China 131 P 2002 1.4 1.4 0.3+0.003H 0.4 6-10 61 Rhyolite, gravel 5000 1922

Shapulong China 65 P UC 1.3 1.3 0,4 4-5 7 Tuff lava 450 9Shedong China 50 UC 8Shewang China 36 W 1994 1.3 1.3 .15(shortcrete) 4 7 Tuff lava 120 3

Shisanling (Upper) China 75 P 1994 1.5 1.7 0,3 0.5-0.6 32 Andesite 2700 4Shuanggou China 110 P UD 1.4 1.4 0.3+0.003H h0.3, v.4 3.5-5.5 41 Andesite, basalt 2580 391Shuibaya China 232 P UD 1.4 1.4 0.3+0.003H 0.4 4-10 Limestone 15 500 4700Songshan China 79 P UC 1.4 1.4 0.3+0.003H 0,5 6-8 24 Andesite 1420 123Suojinshan China 62 UC 600 100

Taian China 40 P UD 1.3 1.3Tankeng China 161 P UD 1.4 1.4 0.3+0.003H 0.4 6-10 68 Tuff lava 10 000 3530Tanzitan China 62 UC 1.35 1.35 0,4 0,4 4 36 Sandstone, 630 12

Tasite China 43 I UC 1.6 1.6 Panel wall, gravel 450 12Tianhuangping China 95 P 1997 1.4 1.3 0.3+0.002H 0,4 4-6 21 Rhyolite, tuff lava 1420 9

Tianshengqiao No.1 China 178 P/I/F UC 1.4 1.4 0.3+0.005H 0,4 4-9 156 Limestone 17 690 10 260Tongjiezi Saddle China 48 P 1992 1.65 1.7 0.3, 0.4 0.42, 0.63 2.5-3 15 Gravel, basalt, 700 200

Wananxi China 94 P 1995 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 18 Granite, porphry 1290 228Wawushan China 140 I/P UD 545Wuluwati China 135 F/I/P UC 1.6 1.6 0.3+0.003H h 0.4, v 0.5 6-10 76 Gravel, schist 6800 340

Xiangshuijian China 153 P UD 1.4 1.4 2570 17Xiaogan Gou China 55 P 1990 1.55 1.6 0,3 0,55 3.5-4.5 5 Gravel 240 10Xiaolongtou China 36 1995Xiaomeisha China 49 W 1995 1.4 1.4 0,35 0,4 3-4 6 Granite 220 1,5Xiaoshan China 86 P 1997 1.4 1.4 0.3+0.003H h0.37, v.4-.5 6-8 36 Andesite 1430 97Xiaoxikou China 68 I/P UC 1.4 1.3 0,4 20 Limestone 1110 66Xibeikou China 95 P/I/F 1990 1.4 1.4 0.3+0.003H 0,4 5-6 29.5 Limestone 1620 210

Xikou Lower China 43 P 1997 1.4 1.5, 1.6 0,3 0,426 4 11 Tuff 440 1Xikou Upper China 38 P 1996 1.4 1.3-1.4 0,3 0,426 4 6 Conglomerate 140 1Yaojiaping China 180 P UDYaoshui China 103 UD 1.4 1.55 29 1720 52

Yubeishan China 74 UC 38 890 860Yutiao China 110 W/P/I UD 30 Sandstone 1630 95Zeya China 79 W/F/P 1997 1.3 1.3 0,4 0,4 3.5-6 Tuff lava 1420 57

Zhushuqiao China 78 I/F/H 1990 1.4 1.7 0.3+0.003H h0.35, v0.4 3.5-5.0 23 Limestone/slate 820 278Zipingpu China 159 P UD 1.4 1.5 0.3+0.003H 5, 8, 15 127 Sandstone 11 670 1080

Alto Anchicaya Colombia 140 P 1974 1.4 1,4 0.3+0.003H 0,5 7 22 Hornfeld 2400Andaqui Colombia 160 ZCercado Colombia 120 2003 1.4 1.4 0.3+0.002H 0.35H 0.4V 3-6 37 Vulcanite 2900 198

Chuza (Gollilas) Colombia 130 W/P 1978 1.6 1,6 0.3+0.0037H 0,4 3.0 1,4 GravelLa Regadera II Colombia 90 W 2002 1.5 1.6 0.3+0.002H 0.3H 0.35V 3 Gravel

Porce III Colombia 145 P ZQuimbo Colombia 150 P Z 1.5,1.6 GravelSalvajina Colombia 148 1983 1.5 1.4 0.3+0.0031H 0,4 4.0-8.0 50 Dredger tailings 4100

Sogamoso Colombia 190 P 2004 1.4 1.4 0.3+0.002H 0.3 0.4 6-10 75 GravelCabin Creek Colorado, USA 76 P 1967 1.3 1,75 0.3+0.0067H 0,5 Rock & earthChase Gulch Colorado, USA 40 W 1994

Mazar Equador 171 P 2003Goyeb Ethiopia 130 P UDFades France 70 P 1967 1.3 1,3 0.35+0.0042H 0,5 4 17 Granite

Gandes France 44 1967 1.6 1,3Rouchain France 60 1976 1.4 1,4 0.35+0.0042H 0,5 4 16 Granite

Messochora Greece 135 P/I 1995 1.4 1.4 0.3+0.003H 0,5 0.7 50 LimestoneDhauliganga India 50 H 2003 Gneiss

Batubesi (Larona) Indonesia 30 P 1978 1.3 1,5 0,25 0,3 4 Spill way over damCirata Indonesia 125 P 1987 1.3 1.4 0.35+0.003H 0,4 4, 5, 7 Breccia/andesite

Cirata (Raised) Indonesia 140 P ZSiah Bishe (Lower) Iran 130 P 1994 1.5 1.6 Limestone, basaltSiah Bishe (Upper) Iran 100 P 1994 1.5 1.6 Dolomite,

Ishibuchi Japan 53 1953 1.2 1,4 12 DR-daciteNozori Japan 44 1955 1.3 1,5 0.3+0.011H 0,5 T DR-andesite

Al Wehda Jordan 140 W/I UD 1.3 1.5 0.3+0.003H 0.5 BasaltDix River Kentucky,USA 84 P 1925 1-1.2 1,4 0,5 T DR-limestone 252 220Namgang Korea ROK 34 1995 1.3 1.3 0,35

Sancheng 1 Korea ROK 65 P UD 1.4 1.4 0.3+0.002HSancheng 2 Korea ROK 90 P UD 1.4 1.4 0.3+0.002HYang Yang Korea ROK 93 P 2000 1.4 1.4 0.35 5 Gneiss

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Jilintai Laos 152 UD 1.5 1.5 74 TuffNam Ngum 3 Laos 220 P 2001 1.4 1.4 0.3+0.003H 0.3, 0.11 4-11 5 Sandstone,

Xe Kaman Laos 187 P Z 1.3 1.3 0.3+0.002H 0.35H 0.4V 4-9 84 Sandstone 9200 17 330Xe Namnoy Laos 78 P C

Karaoun Lebanon 66 1963 1.3 1,1Mohale Lesotho 145 I/P 2000 1.4 1.4 0.3+0.0035H 0.4 3+H/15 87 Basalt 7400 938

Houay Ho Loas 85 P 1996 1.4 1.5 0,3 0,52 4-9 22 Sandstone 1250 595Ahnihg Malaysia 74 W/P 1988 1.3 1.3 0,3 0,61 6 16 Quartzite/ 700 235

Babagon Malaysia 63 W 1996 1.3 1.6 0,3 3-5 sandstone, randomBakun Malaysia 205 P UD 1.4 1.4 0.3+0.003H 0.3 0.4 4-6 127 Greywacke, 17 000 43 800

Batang Ai (Main) Malaysia 70 P 1985 1.4 1.4 0,3 0,5 4.6 65 Dolorite 4000 2360Murum Malaysia 141 P Z 1.4 1.4 0.3+0.003H 0.35 3-15 74 Greywacke, 6600 12 043Ulu Al Malaysia 110 P 1989 1.3 1.4 0,61 6 48 Greywacke/

Aguamilpa Mexico 187 P 1993 1.5 1.4 0.3+0.003H 0.3-0.35 137 Graval/ignimbrite 4000 6950El Cajon Mexico 189 P C 1.5 1.4 0.3+0.003H 99 Gravel, 10 000 2368La Parota Mexico 162 P C 1.5 1.4 0.3+0.003H 4-8 170 Gravel, gneiss 12 000 6752Pinzanes Mexico 67 P 1956 1.2 1,3 T

San Ildefonso Mexico 62 1959 1.4 1,4Tetelcingo Mexico 150 P Z 1.5 1.5 0.3+0.002H

Chakoukane Morocco 63 I 1999 1.6 1.6 Gravel panelwall 1800 50Dchar El Qued Morocco 101 I/P 1999 1.4 2.1 0.3+0.003H 0.3 4-5 Rockfill 2000 740

M'dez Morocco 97 I/P Z 1.8 1.6 0.3+0.003H 0.3 3-5 40 Gravel 1900 600Mohammed B.A.K. Morocco 40 W/I 1981 1.9 2.2 0,3 0,4 23 Gravel/panelwall 650 36

Nakhla Morocco 46 W 1961 1.0 1,45 0,3 9 Poor sandstoneTa Seng Myanmar 162 P CWest Seti Nepal 220 P Z 1.5 1.6 0.3+0.003H 0.4 4-11 Gravel 12 500 1604Shiroro Nigeria 130 P 1984 1.3 1.3 0.3+0.003H 0,4 6 50Storvas Norway 80 P 1980 1.3 1.3Fortuna Panama 65 P 1982 1.3 1.4 0.41+0.003H 0,5 4.0 22 Andesite

Fortuna (Raised) Panama 105 P 1994 1.3 1.4 0,15 0,25 4 AndesiteFortuna Raised Panama 105 1984 1.3 1.4 0,15 0,25 4.0 Andesite

Guasquitas Panama 49 P 2001 1.4 1.5 0.3 0.3 3 GravelAntamina Peru 115 Tailings UD 1.3 1.3 0.3 0.35 4 LimestoneHuallaga Peru 140 ZMalpaso Peru 78 1936 0,5 1,33 T Placed & DR Torata Peru 100 W 2002 1.3 1.3 0.3+0.002H 0.3H 0.35V 4Truro Peru 50 1988 1.5 1.5 0,4 0,5 3-5.0 Breccia

Agbulu Philippines 234 P UD 1.4 1.5 21 000 3981Kaliwa Philippines 100 UD

Odeleite Portugal 61 W/I 1988 1.4 1.4 0.5+0.005H 0,5 Schist/greywacke 1000 130Paradela Portugal 112 P 1955 1.3 1,3 0.3+0.00735H 0,5 T 55 DR-granite 2700 165Salazar Portugal 70 1949 1,25 1,4 Steel G DR-siliceous

Vilar Portugal 55 P 1965 1.1-1.3 1,3 0.3+0.00735H 0,5 DR-granite 300 100Bolboci Romania 56 W/P 1985 1.3 1.3 0.3+0.007H 0,4 Gallery 6 Limestone 1000 18Cerna Romania 91 W/P/I 1980 1.3 1.3 0.4+0.002H 0,5 Trench 5,4 Limestone 487 124

Fantanele Romania 92 P/F 1978 1.3 1,3 0.3+0.007H 0,5 Gallery 34,2 Granite 2320 225Fenes Romania 40 W/F UD 1.6 1.5 n/a n/a Trench 5 Granite 245 6.5Lesu Romania 61 1973 1.3 1,3 0.3+0.007H 0,5 T 5 Rhyolite 560 28Oasa Romania 91 1979 1.3 1,6 0,6 0,5 Gallery 24 Schist 1600 136

Pecineagu Romania 105 W/P/I 1984 1.7 1.7 0.35+0.0065H 0,4 Gallery 30 Quartzite 2400 69Poneasca Romania 52 W/P UD 1.3 1.4 0.3+0.001H 0,5 2.5 5.2 Limestone 1000 8Rastolrita Romania 105 P/W 1997 1.5 1.5 0.3+0.003H 0,5 4.0-6.0 30 Andesite 3100 43Rubiales Romania 43 1977 1.4 1,4 PeridotiteRuncv Romania 90 W/P 1999 1.4 1.4 0.3+0.002H 0.45 4.0 26.2 Granite 1900 26Surduc Romania 37 W/I/F 1976 1.5 1,5 0.4+0.005H 0,5 Trench Schist 125 56

Taia Romania 64 UD 1.65 1.55 Gallery 9.7 SchistRoseau Santa Lucia 40 W 1995 1.3 1.5 0,3 0,33 3.3 6.8 AndesiteLungga SolomonsDonbog South Korea 45 1986 1.5 1.5 0.3+0.008H 0,5 5.3 7 AndesiteAcena Spain 65 I UD 1.3 1.3 0.3+0.003H 0,4 3+H/15 GneissAixola Spain 51 W 1982 51 1.35 1,45 375 3

alfilorios Spain 75 W 1983 1.4 1.4 Limestone 345 15Alfilorios Spain 7 W 1990 1.4 1.35 0,3 Gallery Limestone 67 23Alsasua Spain 50 W/I 1985 1.5 1.4 0.3+0.003H 0,4 4.5(Gallery) 14 Limestone

Amalahuigue Spain 60 1983 1.4 1.4Arriaran Spain 50 UD 1.4 1.4

Barrendiola Spain 47 1981 1.6 1.5Bejar Spain 71 I 1984 1.3 1.3 0.35+0.003H 0,4 3-H/15 19 GraniteBejar Spain 71 W 1992 1.3 1.3 3-H/15 19 Granite 763 14

Canvelo Spain 35 UDCarcauz Spain 70 UD

Corumbel Bajo Spain 46 1987 1.5 1.5El Tejo Spain 40 1974 1.3 1,4 0,25 0,25 9 Limestone 270 1

Guadalcacin Spain 78 1988 1.5 1.5 1098 800Ibag-Eder Spain 65 W 1991 750 11,3Ibba Yeder Spain 66 UD 1.35 1.5

Jaraiz de la Vera Spain 46 S 1995Laredo Spain 40 Z 1.3 1.5

Los Campitos Spain 54 1974 1.35 1,4 0,3 0,4 28 Basalt 576 3Mulagua Spain 56 I 1981 1.3 1.3 212Piedras Spain 40 W/F 1967 1.3 1,3 0,25 0,5 4 Sandstone

San Anton Spain 68 1983 1.35 1.35Urkulu Spain 52 W 1981 350 10Yesa Spain 117 I/P UD 1.3 1.5

Kotmale Sri Lanka 97 P 1985 1.4 1.45 0.3+0.003H 0,65 3-8 60 CharnockiteMerowe (Nile) Sudan 83 P Z 1.3 1.4 0.3+0.003H 0.3, 0.4 4-15 GraniteKaeng Krung Thailand 110 P/I Z 1.3 1.3-1.5 0.3Khao Laem Thailand 130 P 1984 1.4 1.4 0.3+0.003H 0,5 4.5(Gallery) 140 Limestone

Kwai Nai-Main Thailand 95 I 2002 1.4 1.4Nam Khek Thailand 125 P/I Z 1.4 1.5 0.4 4-7 59 Conglomerate,

Atasu Turkey 122 W/P 2002 1.4 1.5 0.3+0.0035H 0.4 12 45 Andesite, Basalt 3787 36Dim Turkey 135 I/P/W 2001 1.4 1.5 0.3+0.0035H 0.4 13 51 Schist 4093 250

Gordes Turkey 95 I/W 2001 1.4 1.5 0.35+0.003H 0.4 9 61 Limestone 4700 450

Page 3



Sheet3.1

Kurtun Turkey 133 P 2001 1.4 1.5 0.3+0.003H 0.4 10 35 Granodorite 3026 108Yedigaze Turkey 105 CCaruachi Venezuela 80 P 1999 1,3 1,3 0,35 0,35 3 60 Granite, Gneiss 2000 4

Neveri (Turimiquire) Venezuela 115 W 1981 1.4 1.5 0.3+0.002H 0,5 h3.5-v7.50 53 LimestoneTocoma Venezuela 40 P 2004 1.3 1.3 0.35 0.3H 0.35V 3 Gneiss

Yacambu Venezuela 162 W 1996 1.5 1.6 0.3+0.002H 0,4 Concrete 13 Gravel 435Bailey, R.D. W. Vir, USA 95 F/R 1979 2.0 2.0 0,3 0,5 3.05+0.0019 65 Sandstone

Rama Yugoslavia 110 1967 1.3 1,3 1340 487Mukorsi Zimbabwe 89 I 2002 1.3 1.3 0.4 0.5 4+H/30 22.3 Gneiss 2440 1802

2nd Stage 200 1.3 1.4 mine tailings dam

shale

Min/6M

Concrete/ Siltstone/dam sandstone

greywacke

shortcrete

conglomerate

sandstonedolerite spillway

over dam

sandstone

panel wallLimestone

sandstone

dam

Panel cut off

Mudstone

Page 4



Sheet3.1

SandstonesiltstoneGneiss

Sandstone

mudstone

Spillway over dampanel wallsandstone

spillway over dammudstone

sandstoneignimbrite

Page 5







ShaleLower Bear No.1 Calif, USA 71 P 1952 1,3 1,4 0.3+0.0067H 0,5 T 6 DR-gravel 1002 6,4Lower Bear No.2 Calif, USA 50 P 1952 1.0 1,4 0.3+0.0067H 0,5 T 3 DR-granite






Cabin Creek Colorado, USA 76 P 1967 1.3 1,75 0.3+0.0067H 0,5 Rock & earthFades France 70 P 1967 1.3 1,3 0.35+0.0042H 0,5 4 17 Granite

Gandes France 44 1967 1.6 1,3Piedras Spain 40 W/F 1967 1.3 1,3 0,25 0,5 4 SandstoneRama Yugoslavia 110 1967 1.3 1,3 1340 487


Cethana Australia 110 P 1971 1.3 1,3 0.3+0.002H 0,6 3-5.36 24 Quartzite 1376 109Lesu Romania 61 1973 1.3 1,3 0.3+0.007H 0,5 T 5 Rhyolite 560 28

Alto Anchicaya Colombia 140 P 1974 1.4 1,4 0.3+0.003H 0,5 7 22 Hornfeld 2400



El Tejo Spain 40 1974 1.3 1,4 0,25 0,25 9 Limestone 270 1Los Campitos Spain 54 1974 1.35 1,4 0,3 0,4 28 Basalt 576 3

Kootenay Canal Canada 37 1975 2.0 1,3 0,2 0,6 2-4 20 Gneiss 3000Rouchain France 60 1976 1.4 1,4 0.35+0.0042H 0,5 4 16 GraniteSurduc Romania 37 W/I/F 1976 1.5 1,5 0.4+0.005H 0,5 Trench Schist 125 56



Fantanele Romania 92 P/F 1978 1.3 1,3 0.3+0.007H 0,5 Gallery 34,2 Granite 2320 225

Outardes No.2 Canada 55 P 1978 1.4 1,4 0,3 0,45 3.05 8 GneissBailey, R.D. W. Vir, USA 95 F/R 1979 2.0 2.0 0,3 0,5 3.05+0.0019 65 Sandstone

Oasa Romania 91 1979 1.3 1,6 0,6 0,5 Gallery 24 Schist 1600 136Winneke/Sugarloaf Australia 85 W 1979 1.5 2.2 0.3+0.002H 0,45 0.1H 83 Sandstone 4700 100

Min/6MAreia Brazil 160 P 1980 1.4 1.4 0.3+0.0034H 0,4 4.55, 5.75 139 Basalt 13 000 6100Cerna Romania 91 W/P/I 1980 1.3 1.3 0.4+0.002H 0,5 Trench 5,4 Limestone 487 124

Storvas Norway 80 P 1980 1.3 1.3Barrendiola Spain 47 1981 1.6 1.5Mackintosh Australia 75 P 1981 1.3 1.3 0,25 0,7 3.0-3.86 27 Greywacke 850 949

Mangrove Creek Australia 80 W 1981 1.5 1.6 0.375+0.003H 0,35 3, 4, 5 29 Siltstone 1340 170

Mohammed B.A.K. Morocco 40 W/I 1981 1.9 2.2 0,3 0,4 23 Gravel/panelwall 650 36Mulagua Spain 56 I 1981 1.3 1.3 212

Neveri (Turimiquire) Venezuela 115 W 1981 1.4 1.5 0.3+0.002H 0,5 h3.5-v7.50 53 LimestoneUrkulu Spain 52 W 1981 350 10Aixola Spain 51 W 1982 51 1.35 1,45 375 3


dam sandstoneFortuna Panama 65 P 1982 1.3 1.4 0.41+0.003H 0,5 4.0 22 AndesiteKekeya China 42 I 1982 1.2-2.751.5-1.75 0.3-0.5 0.0 3 12 Gravel, panel wall 440 12

Lyell Australia 46 W 1982Murchison Australia 89 P 1982 1.3 1.3 0,3 0,65 3-4.6 16 Rhyolite 905 97

alfilorios Spain 75 W 1983 1.4 1.4 Limestone 345 15Amalahuigue Spain 60 1983 1.4 1.4



Bastayan Australia 75 P 1983 1.3 1.3 0,25 0,7 3-3.8 19 Rhyolite 600 124Boondoma No.1 Australia 63 W/I 1983 1.3 1.3 0,3 0,4 3.5-5.5 25 RhyoliteGlennies Creek Australia 67 W/I 1983 1.3 1.3 0,3 0,43 3-4 25 Welded tuff 947 284

Salvajina Colombia 148 1983 1.5 1.4 0.3+0.0031H 0,4 4.0-8.0 50 Dredger tailings 4100greywacke

San Anton Spain 68 1983 1.35 1.35Bejar Spain 71 I 1984 1.3 1.3 0.35+0.003H 0,4 3-H/15 19 Granite

Fortuna Raised Panama 105 1984 1.3 1.4 .15(shortcrete) 0,25 4.0 AndesiteKhao Laem Thailand 130 P 1984 1.4 1.4 0.3+0.003H 0,5 4.5(Gallery) 140 LimestonePecineagu Romania 105 W/P/I 1984 1.7 1.7 0.35+0.0065H 0,4 Gallery 30 Quartzite 2400 69

Shiroro Nigeria 130 P 1984 1.3 1.3 0.3+0.003H 0,4 6 50

Alsasua Spain 50 W/I 1985 1.5 1.4 0.3+0.003H 0,4 4.5(Gallery) 14 LimestoneBatang Ai (Main) Malaysia 70 P 1985 1.4 1.4 0,3 0,5 4.6 65 Dolorite 4000 2360

Bolboci Romania 56 W/P 1985 1.3 1.3 0.3+0.007H 0,4 Gallery 6 Limestone 1000 18Kotmale Sri Lanka 97 P 1985 1.4 1.45 0.3+0.003H 0,65 3-8 60 Charnockite

Terror Lake Alaska 58 1985 1.5 1.4 0.3+0.003H 0,4 GreywackeDonbog South Korea 45 1986 1.5 1.5 0.3+0.008H 0,5 5.3 7 AndesiteKoman Albania 133 P 1986


Corumbel Bajo Spain 46 1987 1.5 1.5

Split Rock Australia 67 I 1987 1.3 1.3 0,3 0,35 Greywacke/gravel 1048 398 White Spur Australia 45 P 1988 1.3 1.3 0,25 0,5 3-4.2 5 Tuff (Cambrian)

Ahnihg Malaysia 74 W/P 1988 1.3 1.3 0,3 0,61 6 16 Quartzite/ 700 235conglomerrate

Balsam Meadows Calif, USA 40 P 1988 1.4 1.4 GraniteGuadalcacin Spain 78 1988 1.5 1.5 1098 800Guamenshan China 59 W/F/I/P 1988 1.4 1.3 0.3+0.003H 0,38 3-5 8 Andesite 440 81

Odeleite Portugal 61 W/I 1988 1.4 1.4 0.5+0.005H 0,5 Schist/greywacke 1000 130Spicer Meadow Calif, USA 82 P 1988 1.4 1.4 0.3+0.003H 0.4 6 Granite

Truro Peru 50 1988 1.5 1.5 0,4 0,5 3-5.0 BrecciaBradley Lake Alaska, USA 40 P 1989 1.6 1.6 0,3 0,5 4-5 GreywackeChengbing China 75 P 1989 1.3 1.3 0.3+0.0027H h 0.3, v 0.5 3-12 16 Tuff lava 800 52

Gouhou China 70 W/I 1989 1.6 1.55 0.3+0.004H 0.35-0.5 4-5 22 Gravel (silty) 890 3

Ulu Al Malaysia 110 P 1989 1.3 1.4 0,61 6 48 Greywacke/sandstone

Alfilorios Spain 7 W 1990 1.4 1.35 0,3 Gallery Limestone 67 23PDF created with pdfFactory Pro trial version www.pdffactory.com


Crotty Australia 82 P 1990 1.3 1.5 0,3 0,5 3-4.2 13 Gravel quartzite/ 784 1060dolerite spillway overdam

Longxi China 59 I/F/H 1990 1.3 1.3 0,4 h 0.3, v 0.5 3-5 7 Tuff lava 300 26Luocun China 58 I 1990 1.2 1.2-1.4 0,3 0.4-0.5 5-6 12 Dumped rock/ 640 21

sandstone

Xiaogan Gou China 55 P 1990 1.55 1.6 0,3 0,55 3.5-4.5 5 Gravel 240 10Xibeikou China 95 P/I/F 1990 1.4 1.4 0.3+0.003H 0,4 5-6 29.5 Limestone 1620 210

Zhushuqiao China 78 I/F/H 1990 1.4 1.7 0.3+0.003H h0.35, v0.4 3.5-5.0 23 Limestone/slate 820 278Ibag-Eder Spain 65 W 1991 750 11,3

Bejar Spain 71 W 1992 1.3 1.3 3-H/15 19 Granite 763 14Doulanggou China 35 I 1992 7 Limestone 100 3,5

Guangzhou Upper China 68 P 1992 1.4 1.4 0.3+0.003H 0,4 3-6 18 Granite 800 17Hengshan (raised) China 70 W/I/P 1992 1.4 1.3 0,3 0,4 4.4 10 Tuff lava, panel wall 1090 112

Segredo Brazil 145 P 1992 1.3 1.2-1.4 0.3+0.0035H 0.3, 0.4 4-6.5 86 Basalt 6700 3000Tongjiezi Saddle China 48 P 1992 1.65 1.7 0.3, 0.4 0.42, 0.63 2.5-3 15 Gravel, basalt, 700 200

Aguamilpa Mexico 187 P 1993 1.5 1.4 0.3+0.003H 0.3-0.35 137 Graval/ignimbrite 4000 6950Anthony Australia 47 P 1993 1.3 1.3 3-4 4 110 39Huashan China 81 P 1993 1.4 1.4 0.3+0.003H h 0.4, v 0.5 3-6 13 Granite 700 63

Baiyanghe China 37 I 1994 1.7 1.5 0.3+0.003H 0,5 2, 2.8, 3.8 21 Gravel 370 6Chase Gulch Colorado, USA 40 W 1994


Shewang China 36 W 1994 1.3 1.3 .15(shortcrete) 4 7 Tuff lava 120 3Shisanling (Upper) China 75 P 1994 1.5 1.7 0,3 0.5-0.6 32 Andesite, 2700 4

limestoneSiah Bishe (Lower) Iran 130 P 1994 1.5 1.6 Limestone, basalt

Siah Bishe (Upper) Iran 100 P 1994 1.5 1.6 DolomiteXingo Brazil 150 P 1994 1.4 1.3 0.3+0.0029H 0,4 5-7 135 Granite gneiss 12 300 3800

Caoyutan China 16 I/P 1995 1.6 1.5 0,3 h0.3, v0.5 1.5 12 Gravel 27Dongjin China 89 W/P/I 1995 1.4 1.3 0.3+0.0023H 0,4 4-8 28 sandstone 1760 800

Jaraiz de la Vera Spain 46 S 1995Messochora Greece 135 P/I 1995 1.4 1.4 0.3+0.003H 0,5 0.7 50 LimestoneNamgang Korea ROK 34 1995 1.3 1.3 0,35

Pichi-Pic un-leufu Argentina 40 P 1995 1.5 1.5 0,3 0,35 4 Gravel, panel wallRoseau Santa Lucia 40 W 1995 1.3 1.5 0,3 0,33 3.3 6.8 Andesite

Santa Juana Chile 110 W/I 1995 1.5 1.6 0.3+0.002H 0,3 3-5 Gravel, panel wall 390 160

Wananxi China 94 P 1995 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 18 Granite, porphry 1290 228Xiaolongtou China 36 1995Xiaomeisha China 49 W 1995 1.4 1.4 0,35 0,4 3-4 6 Granite 220 1,5

Babagon Malaysia 63 W 1996 1.3 1.6 0,3 3-5 sandstone, randomChalong China 39 I 1996 1.8 1.8 0,4 0,45 3-4 9 Gravel 370 138



Douyan China 58 P 1996 1.4 1.6 0,3 h0.34, v0.52 4-5 19 Granite 520 98Haichaoba China 57 I 1996 1.4 1.3-1.4 0,35 h 0.4, v 0.5 4-5 13 Granite 480 7Houay Ho Loas 85 P 1996 1.4 1.5 0,3 0,52 4-9 22 Sandstone 1250 595Nanche China 64 I/P/F 1996 1.4 1.4 0.3-0.45 0,425 3.5-5.5 12 Sandstone 460 153Pingtan China 55 I/S 1996 390 11Shankou China 39 P/I 1996 1.4 1.4 0,3 0,4 3 9 Tuff 650 46

Xikou Upper China 38 P 1996 1.4 1.3-1.4 0,3 0,426 4 6 Conglomerate 140 1Yacambu Venezuela 162 W 1996 1.5 1.6 0.3+0.002H 0,4 Concrete 13 Gravel 435

damBadu China 58 I/W/F/P 1997 1.3 1.3 6 Tuff lava 840 32

Bastonia ? 110 1997 1.5 1.5 0.3+0.003H 0,5 4.6 30 Andesite

Francis Creek Australia I 1997 1.3 1.3 0,3 3-5 Spillway overcrestLianghui China 35 W/I/F/P 1997 1.4 1.4 0,35 0,8 3.5-4.5 22 Panel wall, gravel 680 31Lianhua China 72 P/F/I 1997 1.4 1.4 0.3+0.003H h 0.4, v 0.5 4-6 75 Granite 4230 4180

Meixi China 38 I 1997 1.4 1.3 0,35 0,4 Panel wall 37 Panel wall, gravel 1200 265Rastolrita Romania 105 P/W 1997 1.5 1.5 0.3+0.003H 0,5 4.0-6.0 30 Andesite 3100 43

Tianhuangping China 95 P 1997 1.4 1.3 0.3+0.002H 0,4 4-6 21 Rhyolite, tuff lava 1420 9Xiaoshan China 86 P 1997 1.4 1.4 0.3+0.003H h0.37, v.4-.5 6-8 36 Andesite 1430 97

Xikou Lower China 43 P 1997 1.4 1.5, 1.6 0,3 0,426 4 11 Tuff 440 1Zeya China 79 W/F/P 1997 1.3 1.3 0,4 0,4 3.5-6 Tuff lava 1420 57

Baiyun China 120 P 1998 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 15 Limestone, 1700 360

Cengang China 28 W/I 1998 1.4 1.4 0,35 0,4 3 11 Panel wall, tuff lava 310 6Liangchahe China 43 I/F/P 1998 1.5 1.6 0,3 0.35-0.4 4-5 17 Gravel 510 63

Caruachi Venezuela 80 P 1999 1,3 1,3 0,35 0,35 3 60 Granite, Gneiss 2000 4Chakoukane Morocco 63 I 1999 1.6 1.6 Gravel panelwall 1800 50

Daiqiad China 91 S/I/P 1999 1.5 1.7 0.3-0.5 0.3 2090 158Dchar El Qued Morocco 101 I/P 1999 1.4 2.1 0.3+0.003H 0.3 4-5 Rockfill 2000 740

Ita Brazil 125 P 1999 1.3 1.3 0.3+0.0025H 0.3H 0.4V 4-6 110 Basalt 9300 5100Runcv Romania 90 W/P 1999 1.4 1.4 0.3+0.002H 0.45 4.0 26.2 Granite 1900 26Daao China 90 1999 1.4 1.4 0.3-0.6 26 Sandstone 1450 278Dahe China 68 P/F 1999 1.4 1.4 0,4 3-5 Limestone, slate 900 332

Daqiao China 91 W/I/P 1999 1.5 1.7 0.3-0.5 0.3 6-9 30 Gravel 2090 658Gaotang China 111 P 1999 26 Granite 1950 96

Kalangguer China 62 P/F/W/I 1999 1.5 1.4 0.3+0.003H h 0.4, v 0.5 5-6 36 Gravel, Andesite 1200 39Sanchaxi China 89 UC 14 770 47Gordes Turkey 95 I/W 2001 1.4 1.5 0.35+0.003H 0.4 9 61 Limestone 4700 450

Guasquitas Panama 49 P 2001 1.4 1.5 0.3 0.3 3 GravelKurtun Turkey 133 P 2001 1.4 1.5 0.3+0.003H 0.4 10 35 Granodorite 3026 108

Nam Ngum 3 Laos 220 P 2001 1.4 1.4 0.3+0.003H 0.3, 0.11 4-11 5 Sandstone,Atasu Turkey 122 W/P 2002 1.4 1.5 0.3+0.0035H 0.4 12 45 Andesite, Basalt 3787 36



Kwai Nai-Main Thailand 95 I 2002 1.4 1.4

La Regadera II Colombia 90 W 2002 1.5 1.6 0.3+0.002H 0.3H 0.35V 3 GravelMachadinho Brazil 125 P 2002 1.3 1.3 0.3+0.0033H 0.3 3-6 93 Sandstone 6800

Mukorsi Zimbabwe 89 I 2002 1.3 1.3 0.4 0.5 4+H/30 22.3 Gneiss 2440 1802Shanxi China 131 P 2002 1.4 1.4 0.3+0.003H 0.4 6-10 61 Rhyolite, gravel 5000 1922Torata Peru 100 W 2002 1.3 1.3 0.3+0.002H 0.3H 0.35V 4

Cercado Colombia 120 2003 1.4 1.4 0.3+0.002H 0.35H 0.4V 3-6 37 Vulcanite 2900 198Dhauliganga India 50 H 2003 Gneiss

panel cut offItatebi Brazil 100 2003 1.3 1.3 0.42 0.35H 0.4V 3-5 70 Gneiss, Diorite 3100 1650Mazar Equador 171 P 2003

Sogamoso Colombia 190 P 2004 1.4 1.4 0.3+0.002H 0.3 0.4 6-10 75 GravelTocoma Venezuela 40 P 2004 1.3 1.3 0.35 0.3H 0.35V 3 Gneiss

Baixi China 124 W/I/P UC 1.4 1.4 0.3+0.003H 0.4 5-8 48 Tuff lava 3600 168Sandstone

Bakun China 124 W/I/F/P UC 1.55 1.4 0.3+0.0035H 0.3, 0.4 4-7 79 Gravel, Granite 5500 182Bayibuxie China 35 I UC Gravel 200 4Chaishitan China 103 I/P UC 1,4 1,4 0.3+0.003H 6-7 38 Dolomite 2170 437Chusong China 40 P/I UC 1.8 1.3 0.3 0.4 Gravel 700 15

Douling China 89 P/I/W/F UC 1.4 1.6 32 Limestone, Phylite 2240 485

Gudongkou China 120 I/F/P UC 1.4 1.5 0.3+0.003H h 0.4, v 0.5 4.5-10 Gravel, limestone 1900 138Heiquan China 124 W/I/P UC 1.55 1.4 0.3+0.0035H 0.3, 0.4 4-7 79 Gravel, gneiss 5500 182

Liangjiao China 55 UC 21 Granite 1110 210Motuola China 36 UC



Qiezishan China 107 I/P UC 1.4 1.4 0.3+0.003H 0.3, 0.4 5-7 Granite 1400 121Qinshan China 122 P UC 1.4 1.35 0.3+0.003H 0,5 5, 6, 8 42 Tuff 3100 265

Sanguozhuang China 64 I/P/F UC 20 Basalt 800 15Shapulong China 65 P UC 1.3 1.3 0,4 4-5 7 Tuff lava 450 9Shedong China 50 UC 8Songshan China 79 P UC 1.4 1.4 0.3+0.003H 0,5 6-8 24 Andesite 1420 123Suojinshan China 62 UC 600 100Tanzitan China 62 UC 1.35 1.35 0,4 0,4 4 36 Sandstone, 630 12Tasite China 43 I UC 1.6 1.6 Panel wall, gravel 450 12

Tianshengqiao No.1 China 178 P/I/F UC 1.4 1.4 0.3+0.005H 0,4 4-9 156 Limestone 17 690 10 260Wuluwati China 135 F/I/P UC 1.6 1.6 0.3+0.003H h 0.4, v 0.5 6-10 76 Gravel, schist 6800 340Xiaoxikou China 68 I/P UC 1.4 1.3 0,4 20 Limestone 1110 66Yubeishan China 74 UC 38 890 860

Acena Spain 65 I UD 1.3 1.3 0.3+0.003H 0,4 3+H/15 GneissAgbulu Philippines 234 P UD 1.4 1.5 21 000 3981

Al Wehda Jordan 140 W/I UD 1.3 1.5 0.3+0.003H 0.5 BasaltAntamina Peru 115 Tailings UD 1.3 1.3 0.3 0.35 4 LimestoneArriaran Spain 50 UD 1.4 1.4Bakun Malaysia 205 P UD 1.4 1.4 0.3+0.003H 0.3 0.4 4-6 127 Greywacke, 17 000 43 800

Siltstone

Bocaina Brazil 80 P UD 1.3Canvelo Spain 35 UDCarcauz Spain 70 UD

Centianhe raised China 110 P UD 2500 1600Daliushu China 156 I/P UD 1.6 1.8 0.3-0.8 0.35 6-10 164 Sandstone 14 500 10 743Diguillin Chile I UDFenes Romania 40 W/F UD 1.6 1.5 n/a n/a Trench 5 Granite 245 6.5

Gongbaixia China 130 P UD 1.4 1.4 0.3+0.003H 0.4 4-8 46 Granite, Gravel 4550 550Goyeb Ethiopia 130 P UD

Hongjiadu China 182 P UD 1.4 1.4 0.3+0.003H 0.5 6-10 76 Limestone, 10 000 4590Sandstone

Ibba Yeder Spain 66 UD 1.35 1.5Jiemian China 126 P/I/F UD 58 Sandstone, 3420 1058

mudstoneJilingtai China 152 P UD 1.5 1.9 0.3+0.003H 0.5, 0.4 6-10 74 Tuff 9200 2440Jilintai Laos 152 UD 1.5 1.5 74 TuffJishixia China 100 P UD 1.5 1.55 0.3+0.003H 0.4, 0.5 4, 6, 7.4 Gravel, ballast 2880 264

Kaliwa Philippines 100 UDPankou China 123 P UD 1.4 1.5 0.3+0.0038H 0.5 4-7.5 46 Limestone 3460 2460



Panshitou China 101 W/F/I/P UD 1.4 1.5 0.3-0.5 0.3, 0.4 75 Sandstone, shale 5290 679Poneasca Romania 52 W/P UD 1.3 1.4 0.3+0.001H 0,5 2.5 5.2 Limestone 1000 8Sanbanxi China 179 P UD 1.4 1.4 0.3+0.0035H 0.4 6-12 94 Sandstone 960 4170

Sancheng 1 Korea ROK 65 P UD 1.4 1.4 0.3+0.002HSancheng 2 Korea ROK 90 P UD 1.4 1.4 0.3+0.002HSanta Rita Brazil 85 P UD 1.3 1.3Shuanggou China 110 P UD 1.4 1.4 0.3+0.003H h0.3, v.4 3.5-5.5 41 Andesite, basalt 2580 391Shuibaya China 232 P UD 1.4 1.4 0.3+0.003H 0.4 4-10 Limestone 15 500 4700

Taia Romania 64 UD 1.65 1.55 Gallery 9.7 SchistTaian China 40 P UD 1.3 1.3

Tankeng China 161 P UD 1.4 1.4 0.3+0.003H 0.4 6-10 68 Tuff lava 10 000 3530Wawushan China 140 I/P UD 545

Xiangshuijian China 153 P UD 1.4 1.4 2570 17Yaojiaping China 180 P UDYaoshui China 103 UD 1.4 1.55 29 1720 52

Yesa Spain 117 I/P UD 1.3 1.5Yutiao China 110 W/P/I UD 30 Sandstone 1630 95

Zipingpu China 159 P UD 1.4 1.5 0.3+0.003H 5, 8, 15 127 Sandstone 11 670 1080

Andaqui Colombia 160 ZAwonga Raised Australia 63 Z

Babaquara Brazil 80 P Z 1.3 1.3 0.3Bajiaotan China 70 Z 1.4 1.4 Shale

Barra Grande Brazil 170 P ZBoon. Stage 2 Australia 73 ZCampos Novos Brazil 210 P ZCirata (Raised) Indonesia 140 P ZCuesta Blanca Argentina 80 Z 1.4 1.5 0.3+0.003H


Huallaga Peru 140 ZHuangliao China 40 Z 1.4 1.4 0.25 0.35 3 2 Tuff lava,

spillway over damJurua Brazil 40 P Z 1.3 1.3 0.25

Kaeng Krung Thailand 110 P/I Z 1.3 1.3-1.5 0.3Laredo Spain 40 Z 1.3 1.5

Los Molles Argentina 46 Z 1.5 1.5 0.3+0.003H 6 12 Gravel 730 20 000Man.Cr.Raised Australia 105 W Z 1.5 1.6 0.3+0.003H 0.35 3, 4, 5 34 Siltstone/

M'dez Morocco 97 I/P Z 1.8 1.6 0.3+0.003H 0.3 3-5 40 Gravel 1900 600Merowe (Nile) Sudan 83 P Z 1.3 1.4 0.3+0.003H 0.3, 0.4 4-15 Granite

Murum Malaysia 141 P Z 1.4 1.4 0.3+0.003H 0.35 3-15 74 Greywacke, 6600 12 043PDF created with pdfFactory Pro trial version www.pdffactory.com


mudstoneNam Khek Thailand 125 P/I Z 1.4 1.5 0.4 4-7 59 Conglomerate,

sandstonePipay-Guazu 2 Argentina 73 Z 1.3 1.3 0.3+0.004H

Porce III Colombia 145 P ZQuimbo Colombia 150 P Z 1.5,1.6 Gravel


West Seti Nepal 220 P Z 1.5 1.6 0.3+0.003H 0.4 4-11 Gravel 12 500 1604Xe Kaman Laos 187 P Z 1.3 1.3 0.3+0.002H 0.35H 0.4V 4-9 84 Sandstone 9200 17 330

2nd Stage 200 1.3 1.4 mine tailings dam


La Parota Mexico 162 P C 1.5 1.4 0.3+0.003H 4-8 170 Gravel, gneiss 12 000 6752Lungga Solomons CTa Seng Myanmar 162 P C

Xe Namnoy Laos 78 P CYedigaze Turkey 105 C



Rockfill ReservoirName Country Height Purpose Year Slope Face skab Reinforcing Plinth Face area Type Volume capacity

m Completed US DS t=m+CH each way width, m 10³m² 10³m³ 10⁶m³


Venustiano Carranza Mexico 35 I 1930 1.75:1 2.1-3.1 T Earth 1250 1375Salt Springs Calif, USA 100 P/W 1931 1.1-1.4 1,4 0.3+0.0067H 0,5 T 11 DR-granite 2294 171

Cogswell Calif, USA 85 F 1934 1,35 1,6 0,3 T DR-granite 799 13Malpaso Peru 78 1936 0,5 1,33 T Placed & DR Caritaya Chile 70 I 1935 1.5 1.5 0.3-0.35 T 5 DR 42Cogoti Chile 85 I 1939 1.4 1.5 0.2+0.008H T 16 DR-gravel 700 150Madero Mexico 52 I 1939 1.2:1 1.4:1 TMixcoac Mexico 32 F 1941 1.2:1 1.4:1 T 400 2

San Ildefonso Mexico 62 I/C 1942 1.4:1 1.4:1 T Basalt 370 63Colorines Mexico 32 P 1944 1.4:1 1.1-1.3:1 T Basalt 95 263Salazar Portugal 70 1949 1,25 1,4 Steel G DR-silliceous,Shale

Lower Bear No.1 Calif, USA 71 P 1952 1,3 1,4 0.3+0.0067H 0,5 T 6 DR-gravel 1002 6,4Lower Bear No.2 Calif, USA 50 P 1952 1.0 1,4 0.3+0.0067H 0,5 T 3 DR-granite


Paradela Portugal 112 P 1955 1.3 1,3 0.3+0.00735H 0,5 T 55 DR-granite 2700 165Los Pinzanes Mexico 67 P 1956 1.2:1 1.5:1 T 308 4

Wishon Calif, USA 82 P/I 1958 1.0-1.3 1,4 0.3+0.0067H 0,5 T DR-granite 2829 158Courtright Calif, USA 98 P/I 1958 1.0-1.3 1,3 0.3+0.0067H 0,5 T DR-granite 1193 152

Nakhla Morocco 46 W 1961 1.0 1,45 0,3 9 Poor sandstoneKaraoun Lebanon 66 1963 1.3 1,1


Gandes France 44 1967 1.6 1,3Fades France 70 P 1967 1.3 1,3 0.35+0.0042H 0,5 4 17 Granite

Piedras Spain 40 W/F 1967 1.3 1,3 0,25 0,5 4 Sandstone 461 60Cabin Creek Colorado, USA 76 P 1967 1.3 1,75 0.3+0.0067H 0,5 Rock & earth

Rama Yugoslavia 110 1967 1.3 1,3 1340 487


Cethana Australia 110 P 1971 1.3 1,3 0.3+0.002H 0,6 3-5.36 24 Quartzite 1376 109

All above dams are of dumped rockfill (DR) - All dams after 1966 are of compacted rockfill (CR)

Memo No. 134 pg.1 of 11Mar 2004




m Completed US DS =m+CH each way width, m 10³m² 10³m³ 10⁶m³

Lesu Romania 61 1973 1.3 1,3 0.3+0.007H 0,5 T 5 Rhyolite 560 28Sierra Spain 32 1973 1.3 1.3 0,3 Gallery Limestone 380 41

Undurraga Spain 36 1973 1.75 1.4 0,25 0,45 Gallery 7 Limestone 200 2

Alto Anchicaya Colombia 140 P 1974 1.4 1,4 0.3+0.003H 0,5 7 22 Hornfeld 2400El Tejo Spain 40 1974 1.3 1,4 0,25 0,25 Gallery 9 Limestone 270 1

Los Campitos Spain 54 1974 1.35 1,4 0,3 0,4 28 Basalt 576 3

Kootenay Canal Canada 37 1975 2.0 1,3 0,2 0,6 2-4 20 Gneiss 3000Conchi Chile 70 I 1975 1.5 1.5 0.25-0.50 T 10 450 22

Rouchain France 60 1976 1.4 1,4 0.35+0.0042H 0,5 4 16 GraniteSurduc Romania 37 W/I/F 1976 1.5 1,5 0.4+0.005H 0,5 Trench Schist 125 56


Outardes No.2 Canada 55 P 1978 1.4 1,4 0,3 0,45 3.05 8 GneissChuza (Gollilas) Colombia 130 W/P 1978 1.6 1,6 0.3+0.0037H 0,4 3.0 1,4 Gravel

Batubesi (Larona) Indonesia 30 P 1978 1.3 1,5 0,25 0,3 4 Spillway over damFantanele Romania 92 P/F 1978 1.3 1,3 0.3+0.007H 0,5 Gallery 34,2 Granite 2320 225

Winneke/Sugarloaf Australia 85 W 1979 1.5 2.2 0.3+0.002H 0,45 0.1H 83 Sandstone 4700 100Oasa Romania 91 1979 1.3 1,6 0,6 0,5 Gallery 24 Schist 1600 136

Bailey, R.D. W. Vir, USA 95 F/R 1979 2.0 2.0 0,3 0,5 3.05+0.0019 65 Sandstone

Areia Brazil 160 P 1980 1.4 1.4 0.3+0.0034H 0,4 4.55, 5.75 139 Basalt 13 000 6100Storvas Norway 80 P 1980 1.3 1.3Cerna Romania 91 W/P/I 1980 1.3 1.3 0.4+0.002H 0,5 Trench 5,4 Limestone 487 124

Peace (initial) S. Korea 80 F 1980 shotcrete

Mackintosh Australia 75 P 1981 1.3 1.3 0,25 0,7 3.0-3.86 27 Greywacke 850 949Mangrove Creek Australia 80 W 1981 1.5 1.6 0.375+0.003H 0,35 3, 4, 5 29 Siltstone 1340 170

Mohammed B.A.K. Morocco 40 W/I 1981 1.9 2.2 0,3 0,4 23 Gravel/panelwall 650 36Villagudin Spain 33 1981 1.3 1.3 250 18,3

Barrendiola Spain 47 1981 1.45 1.55 270 2Urkulu Spain 52 W 1981 1.6 1.4 0,3 0,35 Gallery 9 Limestone 350 10

Mulagua Spain 56 I 1981 1.3 1.3 9 212 1Neveri (Turimiquire) Venezuela 115 W 1981 1.4 1.5 0.3+0.002H 0,5 3.5-7.50 53 Limestone




. Rockfill ReservoirName Country Height Purpose Year Slope Face slab t Reinforcing Plinth Face area Type Volume capacity


Lyell Australia 46 W 1982Awonga Australia 47 I 1982 1.3 1.3 0.3+0.002H 0,75 Existing 30 Mata sediments

Murchison Australia 89 P 1982 1.3 1.3 0,3 0,65 3-4.6 16 Rhyolite 905 97Kekeya China 42 I 1982 1.2-2.751.5-1.75 0.3-0.5 0.0 3 12 Gravel, panel wall 440 12Fortuna Panama 65 P 1982 1.3 1.4 0.41+0.003H 0,5 4.0 22 AndesiteAixola Spain 51 W 1982 51 1.35 1,45 375 3

Boondoma No.1 Australia 63 W/I 1983 1.3 1.3 0,3 0,4 3.5-5.5 25 RhyoliteGlennies Creek Australia 67 W/I 1983 1.3 1.3 0,3 0,43 3-4 25 Welded tuff 947 284

Bastayan Australia 75 P 1983 1.3 1.3 0,25 0,7 3-3.8 19 Rhyolite 600 124Salvajina Colombia 148 1983 1.5 1.4 0.3+0.0031H 0,4 4.0-8.0 50 Dredger tailings 4100

Amalahuigue Spain 60 1983 1.4 1.4 261 1San Anton Spain 68 1983 1.35 1.35 434 12

Shiroro Nigeria 130 P 1984 1.3 1.3 0.3+0.003H 0,4 6 50Fortuna 1st Stage Panama P 1984 1.3 1.4 0,3 0,4 4.0 Andesite

Pecineagu Romania 105 W/P/I 1984 1.7 1.7 0.35+0.0065H 0,4 Gallery 30 Quartzite 2400 69Bejar Spain 71 I 1984 1.3 1.3 0.35+0.003H 0,4 3-H/15 19 Granite 763 14

Khao Laem Thailand 130 P 1984 1.4 1.4 0.3+0.003H 0,5 4.5(Gallery) 140 Limestone

Batang Ai (Main) Malaysia 70 P 1985 1.4 1.4 0,3 0,5 4.6 65 Dolorite 4000 2360Bolboci Romania 56 W/P 1985 1.3 1.3 0.3+0.007H 0,4 Gallery 6 Limestone 1000 18Alsasua Spain 50 W/I 1985 1.5 1.4 0.3+0.003H 0,4 4.5(Gallery) 14 LimestoneKotmale Sri Lanka 97 P 1985 1.4 1.45 0.3+0.003H 0,65 3-8 60 Charnockite


Koman Albania 133 P 1986Reece (L. Pieman) Australia 122 P 1986 1.3 1.3-1.5 0.3-0.001H 0,65 3-9 35 Dolerite 2700 6411

Donbog South Korea 45 1986 1.5 1.5 0.3+0.008H 0,5 5.3 7 Andesite 420 100

Split Rock Australia 67 I 1987 1.3 1.3 0,3 0,35 Greywacke/gravel 1048 398Cirata Indonesia 125 P 1987 1.3 1.4 0.35+0.003H 0,4 4, 5, 7 Breccia/andesite

Corumbel Bajo Spain 46 1987 1.5 1.5

White Spur Australia 45 P 1988 1.3 1.3 0,25 0,5 3-4.2 5 Tuff (Cambrian)Guamenshan China 59 W/F/I/P 1988 1.4 1.3 0.3+0.003H 0,38 3-5 8 Andesite 440 81

Pyonghwa Korea ROK 80 F 1988 1.5 1.5 0.7-1.0 0,5 8.5-11.5 45.3 Gneiss 2737 5,9Ahnihg Malaysia 74 W/P 1988 1.3 1.3 0,3 0,61 6 16 Quartzite/ 700 235Truro Peru 50 1988 1.5 1.5 0,4 0,5 3-5.0 Breccia






Odeleite Portugal 61 W/I 1988 1.4 1.4 0.5+0.005H 0,5 Schist/greywacke 1000 130Lareo Spain 40 1988 Galeria Limestone 167 2,3

Guadalcacin Spain 78 1988 1.5 1.5 1098 800Balsam Meadows Calif, USA 40 P 1988 1.4 1.4 GraniteSpicer Meadow Calif, USA 82 P 1988 1.4 1.4 0.3+0.003H 0.4 6 Granite 1677

Gouhou China 70 W/I 1989 1.6 1.55 0.3+0.004H 0.35-0.5 4-5 22 Gravel (silty) 890 3Chengbing China 75 P 1989 1.3 1.3 0.3+0.0027H h 0.3, v 0.5 3-12 16 Tuff lava 800 52

Ulu Al Malaysia 110 P 1989 1.3 1.4 0,61 6 48 Greywacke,Sandstone

Bradley Lake Alaska, USA 40 P 1989 1.6 1.6 0,3 0,5 4-5 Greywacke

Crotty Australia 82 P 1990 1.3 1.5 0,3 0,5 3-4.2 13 Gravel quartzite/ 784 1060Xiaogan Gou China 55 P 1990 1.55 1.6 0,3 0,55 3.5-4.5 5 Gravel 240 10

Luocun China 58 I 1990 1.2 1.2-1.4 0,3 0.4-0.5 5-6 12 Dumped rock/ 640 21Sandstone

Longxi China 59 I/F/H 1990 1.3 1.3 0,4 h 0.3, v 0.5 3-5 7 Tuff lava 300 26Zhushuqiao China 78 I/F/H 1990 1.4 1.7 0.3+0.003H h0.35, v0.4 3.5-5.0 23 Limestone/slate 820 278

Xibeikou China 95 P/I/F 1990 1.4 1.4 0.3+0.003H 0,4 5-6 29.5 Limestone 1620 210Alfilorios Spain 67 W 1990 1.4 1.35 0,3 Gallery Limestone 347 23

Ibag-Eder Spain 65 W 1991 750 11,3

Segredo Brazil 145 P 1992 1.3 1.2-1.4 0.3+0.0035H 0.3, 0.4 4-6.5 86 Basalt 6700 3000Doulanggou China 35 I 1992 7 Limestone 100 3,5

Tongjiezi Saddle China 48 P 1992 1.65 1.7 0.3, 0.4 0.42, 0.63 2.5-3 15 Gravel, basalt, 700 200Panel Wall


Anthony Australia 47 P 1993 1.3 1.3 3-4 4 110 39Huashan China 81 P 1993 1.4 1.4 0.3+0.003H h 0.4, v 0.5 3-6 13 Granite 700 63

Aguamilpa Mexico 187 P 1993 1.5 1.4 0.3+0.003H 0.3-0.35 137 Graval/ignimbrite 4000 6950

Pindari (Raised) Australia 83 I/F 1994 1.3 1.3 0,3 0,3 4 Rhyolite 2695 312Xingo Brazil 150 P 1994 1.4 1.3 0.3+0.0029H 0,4 5-7 135 Granite gneiss 12 300 3800

Shewang China 36 W 1994 1.3 1.3 .15(shortcrete) 4 7 Tuff lava 120 3Baiyanghe China 37 I 1994 1.7 1.5 0.3+0.003H 0,5 2, 2.8, 3.8 21 Gravel 370 6

Shisanling (Upper) China 75 P 1994 1.5 1.7 0,3 0.5-0.6 32 Andesite,limestone 2700 4






Fortuna Raised Panama 105 1994 1.3 1.4 0,15 0,25 4 AndesiteChase Gulch Colorado, USA 40 W 1994

Pichi-Pic un-leufu Argentina 40 P 1995 1.5 1.5 0,3 0,35 4 Gravel, panel wall(First stage)Santa Juana Chile 110 W/I 1995 1.5 1.6 0.3+0.002H 0,3 3-5 Gravel, panel wall 2700 160

Caoyutan China 16 I/P 1995 1.6 1.5 0,3 h0.3, v0.5 1.5 12 Gravel 27Xiaolongtou China 36 1995Xiaomeisha China 49 W 1995 1.4 1.4 0,35 0,4 3-4 6 Granite 220 1,5

Dongjin China 89 W/P/I 1995 1.4 1.3 0.3+0.0023H 0,4 4-8 28 sandstone 1760 800Wananxi China 94 P 1995 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 18 Granite, porphry 1290 228

Messochora Greece 135 P/I 1995 1.4 1.4 0.3+0.003H 0,5 0.7 50 LimestoneRoseau Santa Lucia 40 W 1995 1.3 1.5 0,3 0,33 3.3 6.8 Andesite

Jaraiz de la Vera Spain 46 S 1995 1.4 1.4 0,4 12 Granite 320 2

Xikou Upper China 38 P 1996 1.4 1.3-1.4 0,3 0,426 4 6 Conglomerate 140 1Chalong China 39 I 1996 1.8 1.8 0,4 0,45 3-4 9 Gravel 370 138Shankou China 39 P/I 1996 1.4 1.4 0,3 0,4 3 9 Tuff 650 46Pingtan China 55 I/S 1996 390 11

Haichaoba China 57 I 1996 1.4 1.3-1.4 0,35 h 0.4, v 0.5 4-5 13 Granite 480 7Douyan China 58 P 1996 1.4 1.6 0,3 h0.34, v0.52 4-5 19 Granite 520 98Nanche China 64 I/P/F 1996 1.4 1.4 0.3-0.45 0,425 3.5-5.5 12 Sandstone 460 153Booan Korea ROK 50 W/F/P/I 1996 1.4 1.4 0.3+0.0034 0,4 3 18.2 Rhyolite 614 41,5

Houay Ho Loas 85 P 1996 1.4 1.5 0,3 0,52 4-9 22 Sandstone 1250 595Babagon Malaysia 63 W 1996 1.3 1.6 0,3 3-5 sandstone, randomYacambu Venezuela 162 W 1996 1.5 1.6 0.3+0.002H 0,4 Concrete 13 Gravel 2800 435

Francis Creek Australia I 1997 1.3 1.3 0,3 3-5 Spillway overcrestLianghui China 35 W/I/F/P 1997 1.4 1.4 0,35 0,8 3.5-4.5 22 Panel wall, gravel 680 31Poyibuxie China 35 1997 Sandy Gravel 200 4

Meixi China 38 I 1997 1.4 1.3 0,35 0,4 Panel wall 37 Panel wall, gravel 1200 265Xikou Lower China 43 P 1997 1.4 1.5, 1.6 0,3 0,426 4 11 Tuff 440 1

Badu China 58 I/W/F/P 1997 1.3 1.3 6 Tuff lava 840 32Lianhua China 72 P/F/I 1997 1.4 1.4 0.3+0.003H h 0.4, v 0.5 4-6 75 Granite 4230 4180

Zeya China 79 W/F/P 1997 1.3 1.3 0,4 0,4 3.5-6 Tuff lava 1420 57Xiaoshan China 86 P 1997 1.4 1.4 0.3+0.003H h0.37, v.4-.5 6-8 36 Andesite 1430 97

Tianghuangping, China 95 P 1997 1.4 1.3 0.3+0.002H 0,4 4-6 21 Rhyolite, tuff lava 1420 9Lower

Rastolrita Romania 105 P/W 1997 1.5 1.5 0.3+0.003H 0,5 4.0-6.0 30 Andesite 3100 43Bastonia Romania 110 1997 1.5 1.5 0.3+0.003H 0,5 4.6 30 Andesite






Cengang China 28 W/I 1998 1.4 1.4 0,35 0,4 3 11 Panel wall, tuff lava 310 6Liangchahe China 43 I/F/P 1998 1.5 1.6 0,3 0.35-0.4 4-5 17 Gravel 510 63

Baiyun China 120 P 1998 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 15 Limestone, 1700 360San Marcas Spain 33 1998 1.4 1.4 0,3 0,4 2 5 Granite 434 12

Ita Brazil 125 P 1999 1.3 1.3 0.3+0.0025H 0.3H 0.4V 4-6 110 Basalt 9300 5100Chusong China 40 P/I 1999 1.8 1.3 0,3 0,4 T Gravel 700 15

Tasite China 43 I 1999 1.6 1.6 T Panel wall, gravel 450 12Liangjiang China 55 PIF 1999 1.4 1.3 0.3-0.5 4 21 Granite 788 210Danzital China 62 IWP 1999 1.35 0.4 0,4 0,4 4 36 Sandstone-marble 630 12Tanzitan China 62 1999 1.35 1.35 0,4 0,4 4 36 Sandstone 630 12

Dahe China 68 P/F 1999 1.4 1.4 0,4 3-5 Limestone, slate 900 332Xiaozikou China 68 I/P 1999 1.4 1.3 0,4 6 20 Limestone 1110 66

Gangkouwai China 70 C/H/I 1999 1.4 1.4Yubeishan China 74 1999 88 890 860Songshan China 79 P 1999 1.4 1.4 0.3+0.003H 0,5 6-8 24 Andesite 1420 123Sanchaxi China 89 1999 14 770 47

Daao China 90 I/C/H 1999 1.4 1.4 0.3-0.6 0.27-0.36 4-6 26 Sandstone 1450 278Daqiao China 91 W/I/P 1999 1.5 1.7 0.3-0.5 0.3 6-9 30 CR 2090 658

Qiezishan China 107 I/P 1999 1.4 1.4 0.3+0.003H 0.3, 0.4 5-7 26.4 Granite 1400 121Gaotang China 111 P 1999 1,4 1,36 0.4/0.5 8 26 Granite 1950 96

Tianshengqiao No.1 China 178 P/I/F 1999 1.4 1.3 0.3+0.005H 0,4 4-9 156 Limestone 17 690 10 260Namgang Korea ROK 34 W/R/P/I 1999 1.5 1.5 0,35 0,5 5 41.8 Gneiss 1280 309Houay Ho Laos 77 P 1999

Chakoukane Morocco 63 I 1999 1.6 1.6 Gravel panelwall 1800 50Dchar El Qued Morocco 101 I/P 1999 1.4 2.1 0.3+0.003H 0.3 4-5 Rockfill 2000 740

Runcv Romania 90 W/P 1999 1.4 1.4 0.3+0.002H 0.45 4.0 26.2 Granite 1900 26Caruachi Venezuela 80 P 1999 1,3 1,3 0,35 0,35 3 60 Granite, Gneiss 2000 4

Corrales Chile 70 I 2000 1.5 1.6 0.3 - 0.5 0.4 3-4 29 Gravel 1600 50Puclaro Chile 100 I 2000 1.5 1.6 0.3-0.45 0.3 3-4 87 Gravel, Panel Wall 4800 200

Tongpu, west China 37 S 2000 1.4 1.4 0.3 0.45 Panel 9.3 500 235Fengning China 39 P 2000 Sandy Gravel 570 72

Sanguozhuang China 64 I/P/F 2000 20 Basalt 800 15Xiaoba China 65 P/I 2000 CR 710 13

Yushugou China 67.5 I 2000 1.4 1.4 0.3, 0.4 CR 570 11Chaishitan China 103 I/P 2000 1,4 1,4 0.3+0.003H 6-7 38 Dolomite 2170 437Gudongkou China 120 I/F/P 2000 1.4 1.5 0.3+0.003H h 0.4, v 0.5 4.5-10 Gravel, limestone 1900 138

Qinshan China 122 P 2000 1.4 1.35 0.3+0.003H 0,5 5, 6, 8 42 Tuff 3100 265






Heiquan China 124 W/I/P 2000 1.55 1.4 0.3+0.0035H 0.3 0.4 4-7 79 Gravel, gneiss 5500 182Wuluwati China 135 F/I/P 2000 1.6 1.6 0.3+0.003H h 0.4, v 0.5 6-10 76 Gravel, schist 6800 340

Torata Stage I Peru 70 FI 2000 1.6 1.4 0,5 0,4 4 21 Mine waste 2000 3

Matuola China 36 2001Shapulong China 65 P 2001 1.3 1.3 0,4 4-5 7 Tuff lava 450 9Yingchuan China 87 2001 1100

Douling China 89 P/I/W/F 2001 1.4 1.6 32 Limestone, Phylite 2240 485Baixi China 124 W/I/P 2001 1.4 1.4 0.3+0.003H 0.4 5-8 48 Tuff lava 3600 168

Shanxi China 131 P 2001 1.4 1.54 0.3+0.003H 0.4 6-10 70 Rhyolite, gravel 5000 1922Yongdam Korea ROK 70 W/F/P/I 2001 1.4 1.4 0.3+0.003H 0.5 5-8 43 Schist 2198 815Milyang Korea ROK 89 W/F/P/I 2001 1.4 1.4 0.3+0.003H 0.45 5-8 54 Andesite 3763 73.6

Torata Stage II Peru 130 FI 2001 1.6 1.4 0.3 0.4 4 54 Mine Waste 7000 19Gordes Turkey 95 I/W 2001 1.4 1.5 0.35+0.003H 0.4 9 61 Limestone 4700 450Kurtun Turkey 133 P 2001 1.4 1.5 0.3+0.003H 0.4 10 35 Granodorite 3026 108Dim Turkey 135 I/H/S 2001 1.4 1.5 0.3+0.0035H 0.4/0.4 13 51 Schist 4093 250

Itatebi Brazil 112 P 2002 1.25 1.3 0.3+0.002H 0.4 4.6 59 Gneiss, Diorite 5500 1650Machadinho Brazil 125 P 2002 1.3 1.3 0.3+0.0033H 0.3/0.3 3-6 93 Sandstone 6800Kalangguer China 62 H/C/S/I 2002 1.5 1.4 0.3+0.003H 0.4/0.5 5-6 36 Gravel, Andesite 1200 39Dashuigou China 81 2002 760 31Xiantianji China 82 2002 19Yunqiao China 83 P 2002 1500 10Yutiao China 110 S/H/I 2002 1.4 1.4 30 Sandstone 1630 95

Sancheng 1 Korea ROK 65 P 2002 1.4 1.4 0.3+0.002H 0.35/0.48 4-7 31.7 Granulite 2163 6.3Sancheng 2 Korea ROK 90 P 2002 1.4 1.4 0.3+0.002H 0,35/0.48 4-7 23 Gneiss 1690 7.1

Mohale Lesotho 145 WI 2002 1.4 1.4 0.3+0.0035H 0.4 3+H/15 87 Basalt 7400 938Antamina Peru 115 Tailings 2002 1.4 1.4 0.3 0.35/0.35 4 Limestone

Kwai Nai-Main Thailand 95 I 2002 1.4 1.4Atasu Turkey 122 S/H 2002 1.4 1.5 0.3+0.0035H 0.4/0.4 12 45 Andesite, Basalt 3787 36

Catlitkoru Turkey 76 I 2002 1.3 1.3 0.4 0.5/0.5 4+H/30 22.3 Gneiss 2440 1802Mukorsi Zimbabwe 89 I 2002 1.3 1.3 0.4 0.5/0.5 4+H/30 22.3 Gneiss 2440 1802

Los Caracoles Argentina 138 H/I 2003 1.65 1.7 Gravel 8,7 560Quebra-Queixo Brazil 75 P 2003 1.25 1.2 0.3, 0.4 4 Basalt 2100

Cercado Colombia 120 2003 1.4 1.4 0.3+0.002H 0.35, 0.4 3-6 37 Vulcanite 2900 198Dhauliganga India 50 P 2003 Gneiss

Daegok Korea ROK 52 S 2003 1.4 1.8 0.3 0.4/0.4 4.5 27 Gravel, shale 580 28Tamjin Korea ROK 53 S/C/H/I 2003 1.4 1.4 0.3+0.003H 0.4 4-6 26 Tuff 1506 183






Beris Pakistan 40 P 2003 1.4 1.4 0.3-0.002H 0.4Barrigon Panama 82 P 2003 1.45 1.6 0.3 3 Gravel

Pichi Picun Leufu Argentina 54 P 2004 GravelStage II

Punta Negra Argentina 86 2004 1.65 1.71 panel Gravel 7300Potrerillos Argentina 116 P 2004 6400Mashagou China 81 S 2004 1.4 1.5 0.3-0.57 8-5 16 Sandstone 700 7Silanjiang China 103 S 2004 1.4 1.46 0.3-0.65 6-10 75 CR 2100 89Diguillin Chile 92 I 2004 1.5 1.6 0.3+0.002H 0.3, 0.35 5 42 Gravel 2046 80

La Regadera II Colombia 90 S 2004 1.5 1.6 0.3+0.002H 0.3 , 0.35 3 Gravel

Campos Novos Brazil 200 P 2005 1.3 1.4 0.3+0.0025H 0.4 4.5-12 106 Basalt 12000 1480Ruiqiang China 89 I/H/C 2005 1.3 1.3 0.3-0.5 0.3/0.4 3-5 18 Tuff 950 15

Baishuikeng China 101 P 2005 1.4 1.4 0.3-0.55 5-6 CR/CG 1500 25Panshitou China 101 S/C/I/H 2005 1.4 1.5 0.3-0.5 0.3/0.4 75 Sandstone, shale 5290 679Sogamoso Colombia 190 P 2005 1.4 1.4 0.3+0.002H 0.3 0.4 6-10 75 Gravel

Cheongsong, lower Korea, ROK 52 P 2005 1.4 1.4 0.4 4 20 711 7Cheongsong, upper Korea, ROK 95 P 2005 1.4 1.4 0.4 6 34 2145 7

Yang Yang Korea ROK 93 P 2005 1.4 1.4 0.3+0.003H 0.4/0.4 4-5 26 Gneiss 1400 0.5Mirani Pakistan 127 I 2005 1.5 1.6 Gravel

Barra Grande Brazil 185 P 2006 1.3 1.4 0.3+0.0025H 0.4 4.5-10 99 Basalt 13000 5000Monjolinho Brazil 75 P 2006 1.25 1.2 20 1500Berg River South Africa 70 I 2006 1.5 1.5 0.3-0.0024H 0.4 4-8 70 Gravel

Toulnustouc Canada 76 P 2006Tai'an (Upper) China 40 P 2006 1.3 1.3

Guaigui Dominican R. 75 W 2006Mazar Equador 185 P 2006

Karahnjukar Iceland 185 P 2006 1.3 1.3 0.3+0.002H 0.3/0.4 4 Basalt 8500Nam Ngum 3 Laos 220 P 2006 1.4 1.4 0.3+0.003H 0.3/0.4 4-11 5 SandstoneYesa (raised) Spain 117 I/P 2006 1.5 1.6 0.3 0.4 8 44 Gravel 4394 17

Gongbaixia China 130 H 2007 1.4 1.4 0.3+0.003H 0.4 4-8 46 Granite, Gravel 4550 550Jilingtai China 152 P 2007 1.5 1.9 0.3+0.003H 0.5/0.4 6-10 127 Tuff 9200 2440Zipingpu China 159 P 2007 1.4 1.5 0.3+0.003H 5, 8, 15 127 Sandstone 11 670 1080

Hongjiadu China 182 P 2007 1.4 1.4 0.3+0.003H 0.5 6-10 76 Limestone 10 000 4590Shuibuya China 232 P 2007 1.4 1.46 0.3+0.003H 0.4 4-10 12 Limestone 16700 4700El Cajon Mexico 189 P 2007 1.5 1.4 0.3+0.003H 99 Gravel, Ignimbrite 12000 2368






Pai Quere Brazil 150 P 2008 1.3 1.4 0.3+0.002H 0.4/0.5 Basalt 2,600and 0.005H

Sanbanxi China 185 P 2008 1.4 1.4 0.3+0.0035H 0.4 6-12 94 Sandstone 960 4170Mazar Equador 185 P 2008 Quartzite 5000

Nesa (Narmashir) Iran 115 I 2008 1.5 1.8 0.4 0.4 4-7.5 58 Basalt, Gravel 6,000 180Xepain-Xenamnoy Laos 78 P 2008

Xe Kaman Laos 187 P 2008 1.3 1.3 0.3+0.002H 0.35H 0.4V 4-9 84 Sandstone 9200 17 330

Bakun Malaysia 205 P 2009 1.4 1.4 0.3+0.0035H 0.3 0.4 4-6 127 Greywacke 17000 43800Hamdab (Merowe) Sudan 60 I/P 2009 10 km long, granite

Tocoma Venezuela 40 P 2009 1.3 1.3 0.35 0.3 0.35 3 Gneiss

Nagoli Argentina 60 WI UCMedan Bulgaria 92 P UCEl Bato Chile 55 I UC 1.5 1.6 0.34-0.45 3-5 52 Gravel, panel wall 2.380 25

Bayibuxie China 35 I UC Gravel 200 4Motuola China 36 UCShedong China 50 UC 8

Hongzhuhe China 52 UC Limestone 200Suojinshan China 62 P/I/F UC 600 100

Tongbai, lower China 71 P UC 1.4 1.35 0.3+0.003H 0,4 3.5-5 38 1500 129Shianjiang China 103 UC

Jiemian China 126 P/I/F UC 58 Sandstone 3420 1.058Yinzidu China 135 P UC 1.4 1.48 Limestone 3400 527Jilingtai China 157 P UC

Kannaviou Cyprus 75 I UC 1.4 1.8 0.3+0.002H 4-12 35 Basaltic Lavas 1900Guaigui Dominican Re. 75 W UC

Siah Bishe (Upper) Iran 100 P UC 1.5 1.6 Dolomite,Siah Bishe (Lower) Iran 130 P UC 1.5 1.6 Limestone, basalt

Peace (raised) S. Korea 105 F UCIkizdere Turkey 108 I/W UC

Los Molles Argentina 46 UD 1.5 1.5 0.3+0.003H 6 12 Gravel 730 20 000Chihuido Argentina P UDBocaina Brazil 80 P UD 1.3

Santa Rita Brazil 85 P UD 1.3 1.3Catenu Chile 79 I UD 1.5 1.6 0.3-0.47 1 182 Gravel, panel wall 10,010 175

Chacrillas Chile 105 I UD 1.5 1.65 0.3-0.5 0.3/0.35 35 Gravel 2,450 27Puntilla del Viento Chile 105 I UD 1.5 1.6 0.3-0.55 48 Gravel 3,060 85






Punilla Chile 120 I UDHongwawu China 45 UD Shale 400Tongziyun China 70 UD 16 Shale 600Yangjiaxia China 74 UD 36 Limestone 700Hongyan I China 87 UD Gravel 500Laodokou China 97 UD 20 Gravel 1300Jishixia China 100 P UD 1.5 1.55 0.3+0.003H 0.4, 0.5 4, 6, 7, 4 Gravel, basalt 2880 264Taoshui China 103 UD 1.4 1.55 29 1720 52Baisha China 110 UD Slate 2500

Centianhe raised China 110 P UD 2500 1600Shuanggou China 110 P UD 1.4 1.4 0.3+0.003H 0.3, 4 3.5-5.5 41 Andesite, basalt 2580 391

Pankou China 123 P UD 1.4 1.5 0.3+0.0038H 0.5 4-7.5 46 Limestone 3460 2460Jiemian China 126 P/I/F UD 58 Sandstone, 3420 1058

Wawushan China 140 I/P UD 545Xiangshuijian China 153 P UD 1.4 1.4 2570 17

Daliushu China 156 I/P UD 1.6 1.8 0.3-0.8 0.35 6-10 164 Sandstone 14 500 10 743Zipingpu China 159 P UD 1.4 1.5 0.3+0.003H 5, 8, 15 127 Sandstone 11670 1080Tankeng China 161 P UD 1.4 1.4 0.3+0.003H 0.4 6-10 68 Tuff lava 10 000 3530

Yaojiaping China 180 P UDPorce III Colombia 145 P UDGojeb Ethiopia 130 P UD 1.3 1.5 0.3+0.003H 0.4 BasaltKavar Iran 60 UD 1.4 1.7 35

Mirza-Ya-Shirazi Iran 65 I UDLa Parota Mexico 155 P UD 1.4 1.5 0.3+0.003H 4-8 170 Gravel, Gneiss 14158 6790La Yesca Mexico 208 P UD InigbriteWest Seti Nepal 195 P UD 1.5 1.6 0.3+0.003H 0,4 4-11-Panel Gravel 15200 1604Capillucas Peru 37 P UD 1.5 1.5 0.3+0.003H 0,35 3, Blanket 6 Gravel 175 5,1

Morro de Arica Peru 220 P UD 1.4 1.4 0.3+0.003H 0,4 3-5 38 Sandstone, quartzite 5100Kaliwa Philippines 100 UDAgbulu Philippines 234 P UD 1.4 1.5 21 000 3981Fenes Romania 40 W/F UD 1.6 1.5 n/a n/a Trench 5 Granite 245 6.5

Poneasca Romania 52 W/P UD 1.3 1.4 0.3+0.001H 0,5 2.5 5.2 Limestone 1000 8Taia Romania 64 UD 1.65 1.55 Gallery 9.7 Schist

Merowe (Nile) Sudan 83 P UD 1.3 1.4 0.3+0.003H 0.3, 0.4 4-15 GraniteMarmoris Turkey 80 UD

Pipay-Guazu 2 Argentina 73 Z 1.3 1.3 0.3+0.004HCuesta Blanca Argentina 80 Z 1.4 1.5 0.3+0.003HAwonga Raised Australia 63 Z






Boon. Stage 2 Australia 73 ZMan.Cr.Raised Australia 105 W Z 1.5 1.6 0.3+0.003H 0.35 3, 4, 5 34 Siltstone, sandstone

Pai Quero Brazil 160 P ZPunilla Chile 136 IP Z 1.5 1.6 0.3-0.66 0.3H, 0.4V 4-7 84 Gravel 6320 600

Huangliao China 40 Z 1.4 1.4 0.25 0.35 3 2 Tuff lavaBajiaotan China 70 Z 1.4 1.4 ShalePorce III Colombia 145 P ZQuimbo Colombia 150 P Z 1.5, 1.6 GravelAndaqui Colombia 160 Z

Siang Middle India 190 I/P ZCirata (Raised) Indonesia 140 P Z

Murum Malaysia 141 P Z 1.4 1.4 0.3+0.003H 0.35 3-15 74 Greywacke, 6600 12 043Tetelcingo Mexico 150 P Z 1.5 1.5 0.3+0.002H

M'dez Morocco 97 I/P Z 1.8 1.6 0.3+0.003H 0.3 3-5 40 Gravel 1900 600Huallaga Peru 140 ZLaredo Spain 40 Z 1.3 1.5


Boruca Costa Rica 140 C Souapiti Guinea 125 P C 1.7 1.8 0.3+0.003H Gravel

Koi India 167 PI CXe Namnoy Laos 78 P C

Xe Keman 2nd stg. Laos 200 P C 1.3 1.4 Mine tailing damBasha Pakistan 285 C Panel Wall 8800Lungga Solomon Is. P C

Yedigaze Turkey 105 C

LEGEND Purpose column: P = Power I = IrrigationW = Water supply F = Flood control

Year Completed column: XXXX = Year completed or scheduled to be completed,UC = Under Construction (schedule not known),UD = Under Design, Z = Selected in feasibility study,C = Candidate in feasibility study








ShaleLower Bear No.1 Calif, USA 71 P 1952 1,3 1,4 0.3+0.0067H 0,5 T 6 DR-gravel 1002 6,4Lower Bear No.2 Calif, USA 50 P 1952 1.0 1,4 0.3+0.0067H 0,5 T 3 DR-granite






All above dams are of dumped rockfill (DR) - All dams after 1966 are of compacted rocfill (CR).

Cabin Creek Colorado, USA 76 P 1967 1.3 1,75 0.3+0.0067H 0,5 Rock & earthFades France 70 P 1967 1.3 1,3 0.35+0.0042H 0,5 4 17 Granite

Gandes France 44 1967 1.6 1,3Piedras Spain 40 W/F 1967 1.3 1,3 0,25 0,5 4 SandstoneRama Yugoslavia 110 1967 1.3 1,3 1340 487






Cethana Australia 110 P 1971 1.3 1,3 0.3+0.002H 0,6 3-5.36 24 Quartzite 1376 109Lesu Romania 61 1973 1.3 1,3 0.3+0.007H 0,5 T 5 Rhyolite 560 28

Alto Anchicaya Colombia 140 P 1974 1.4 1,4 0.3+0.003H 0,5 7 22 Hornfeld 2400El Tejo Spain 40 1974 1.3 1,4 0,25 0,25 9 Limestone 270 1

Los Campitos Spain 54 1974 1.35 1,4 0,3 0,4 28 Basalt 576 3Kootenay Canal Canada 37 1975 2.0 1,3 0,2 0,6 2-4 20 Gneiss 3000

Rouchain France 60 1976 1.4 1,4 0.35+0.0042H 0,5 4 16 GraniteSurduc Romania 37 W/I/F 1976 1.5 1,5 0.4+0.005H 0,5 Trench Schist 125 56



Fantanele Romania 92 P/F 1978 1.3 1,3 0.3+0.007H 0,5 Gallery 34,2 Granite 2320 225Outardes No.2 Canada 55 P 1978 1.4 1,4 0,3 0,45 3.05 8 Gneiss

Bailey, R.D. W. Vir, USA 95 F/R 1979 2.0 2.0 0,3 0,5 3.05+0.0019 65 SandstoneOasa Romania 91 1979 1.3 1,6 0,6 0,5 Gallery 24 Schist 1600 136

Winneke/Sugarloaf Australia 85 W 1979 1.5 2.2 0.3+0.002H 0,45 0.1H 83 Sandstone 4700 100Min/6M

Areia Brazil 160 P 1980 1.4 1.4 0.3+0.0034H 0,4 4.55, 5.75 139 Basalt 13 000 6100Cerna Romania 91 W/P/I 1980 1.3 1.3 0.4+0.002H 0,5 Trench 5,4 Limestone 487 124

Storvas Norway 80 P 1980 1.3 1.3

Barrendiola Spain 47 1981 1.6 1.5Mackintosh Australia 75 P 1981 1.3 1.3 0,25 0,7 3.0-3.86 27 Greywacke 850 949

Mangrove Creek Australia 80 W 1981 1.5 1.6 0.375+0.003H 0,35 3, 4, 5 29 Siltstone 1340 170Mohammed B.A.K. Morocco 40 W/I 1981 1.9 2.2 0,3 0,4 23 Gravel/panelwall 650 36

Mulagua Spain 56 I 1981 1.3 1.3 212Neveri (Turimiquire) Venezuela 115 W 1981 1.4 1.5 0.3+0.002H 0,5 h3.5-v7.50 53 Limestone

Urkulu Spain 52 W 1981 350 10Aixola Spain 51 W 1982 51 1.35 1,45 375 3


dam sandstoneFortuna Panama 65 P 1982 1.3 1.4 0.41+0.003H 0,5 4.0 22 Andesite





Kekeya China 42 I 1982 1.2-2.751.5-1.75 0.3-0.5 0.0 3 12 Gravel, panel wall 440 12Lyell Australia 46 W 1982

Murchison Australia 89 P 1982 1.3 1.3 0,3 0,65 3-4.6 16 Rhyolite 905 97alfilorios Spain 75 W 1983 1.4 1.4 Limestone 345 15

Amalahuigue Spain 60 1983 1.4 1.4Bastayan Australia 75 P 1983 1.3 1.3 0,25 0,7 3-3.8 19 Rhyolite 600 124

Boondoma No.1 Australia 63 W/I 1983 1.3 1.3 0,3 0,4 3.5-5.5 25 RhyoliteGlennies Creek Australia 67 W/I 1983 1.3 1.3 0,3 0,43 3-4 25 Welded tuff 947 284

Salvajina Colombia 148 1983 1.5 1.4 0.3+0.0031H 0,4 4.0-8.0 50 Dredger tailings 4100greywacke

San Anton Spain 68 1983 1.35 1.35

Bejar Spain 71 I 1984 1.3 1.3 0.35+0.003H 0,4 3-H/15 19 GraniteFortuna Raised Panama 105 1984 1.3 1.4 .15(shortcrete) 0,25 4.0 Andesite

Khao Laem Thailand 130 P 1984 1.4 1.4 0.3+0.003H 0,5 4.5(Gallery) 140 LimestonePecineagu Romania 105 W/P/I 1984 1.7 1.7 0.35+0.0065H 0,4 Gallery 30 Quartzite 2400 69

Shiroro Nigeria 130 P 1984 1.3 1.3 0.3+0.003H 0,4 6 50Alsasua Spain 50 W/I 1985 1.5 1.4 0.3+0.003H 0,4 4.5(Gallery) 14 Limestone

Batang Ai (Main) Malaysia 70 P 1985 1.4 1.4 0,3 0,5 4.6 65 Dolorite 4000 2360Bolboci Romania 56 W/P 1985 1.3 1.3 0.3+0.007H 0,4 Gallery 6 Limestone 1000 18Kotmale Sri Lanka 97 P 1985 1.4 1.45 0.3+0.003H 0,65 3-8 60 Charnockite


Donbog South Korea 45 1986 1.5 1.5 0.3+0.008H 0,5 5.3 7 AndesiteKoman Albania 133 P 1986


Corumbel Bajo Spain 46 1987 1.5 1.5Split Rock Australia 67 I 1987 1.3 1.3 0,3 0,35 Greywacke/gravel 1048 398

White Spur Australia 45 P 1988 1.3 1.3 0,25 0,5 3-4.2 5 Tuff (Cambrian)Ahnihg Malaysia 74 W/P 1988 1.3 1.3 0,3 0,61 6 16 Quartzite/ 700 235

conglomerrateBalsam Meadows Calif, USA 40 P 1988 1.4 1.4 Granite

Guadalcacin Spain 78 1988 1.5 1.5 1098 800





Guamenshan China 59 W/F/I/P 1988 1.4 1.3 0.3+0.003H 0,38 3-5 8 Andesite 440 81Odeleite Portugal 61 W/I 1988 1.4 1.4 0.5+0.005H 0,5 Schist/greywacke 1000 130

Spicer Meadow Calif, USA 82 P 1988 1.4 1.4 0.3+0.003H 0.4 6 GraniteTruro Peru 50 1988 1.5 1.5 0,4 0,5 3-5.0 Breccia

Bradley Lake Alaska, USA 40 P 1989 1.6 1.6 0,3 0,5 4-5 GreywackeChengbing China 75 P 1989 1.3 1.3 0.3+0.0027H h 0.3, v 0.5 3-12 16 Tuff lava 800 52

Gouhou China 70 W/I 1989 1.6 1.55 0.3+0.004H 0.35-0.5 4-5 22 Gravel (silty) 890 3Ulu Al Malaysia 110 P 1989 1.3 1.4 0,61 6 48 Greywacke/

sandstoneAlfilorios Spain 7 W 1990 1.4 1.35 0,3 Gallery Limestone 67 23

Crotty Australia 82 P 1990 1.3 1.5 0,3 0,5 3-4.2 13 Gravel quartzite/ 784 1060dolerite spillway overdam

Longxi China 59 I/F/H 1990 1.3 1.3 0,4 h 0.3, v 0.5 3-5 7 Tuff lava 300 26Luocun China 58 I 1990 1.2 1.2-1.4 0,3 0.4-0.5 5-6 12 Dumped rock/ 640 21

sandstoneXiaogan Gou China 55 P 1990 1.55 1.6 0,3 0,55 3.5-4.5 5 Gravel 240 10

Xibeikou China 95 P/I/F 1990 1.4 1.4 0.3+0.003H 0,4 5-6 29.5 Limestone 1620 210Zhushuqiao China 78 I/F/H 1990 1.4 1.7 0.3+0.003H h0.35, v0.4 3.5-5.0 23 Limestone/slate 820 278Ibag-Eder Spain 65 W 1991 750 11,3

Bejar Spain 71 W 1992 1.3 1.3 3-H/15 19 Granite 763 14Doulanggou China 35 I 1992 7 Limestone 100 3,5


Segredo Brazil 145 P 1992 1.3 1.2-1.4 0.3+0.0035H 0.3, 0.4 4-6.5 86 Basalt 6700 3000Tongjiezi Saddle China 48 P 1992 1.65 1.7 0.3, 0.4 0.42, 0.63 2.5-3 15 Gravel, basalt, 700 200

Aguamilpa Mexico 187 P 1993 1.5 1.4 0.3+0.003H 0.3-0.35 137 Graval/ignimbrite 4000 6950Anthony Australia 47 P 1993 1.3 1.3 3-4 4 110 39Huashan China 81 P 1993 1.4 1.4 0.3+0.003H h 0.4, v 0.5 3-6 13 Granite 700 63

Baiyanghe China 37 I 1994 1.7 1.5 0.3+0.003H 0,5 2, 2.8, 3.8 21 Gravel 370 6Chase Gulch Colorado, USA 40 W 1994


Shewang China 36 W 1994 1.3 1.3 .15(shortcrete) 4 7 Tuff lava 120 3





Shisanling (Upper) China 75 P 1994 1.5 1.7 0,3 0.5-0.6 32 Andesite, 2700 4limestone

Siah Bishe (Lower) Iran 130 P 1994 1.5 1.6 Limestone, basaltSiah Bishe (Upper) Iran 100 P 1994 1.5 1.6 Dolomite

Xingo Brazil 150 P 1994 1.4 1.3 0.3+0.0029H 0,4 5-7 135 Granite gneiss 12 300 3800Caoyutan China 16 I/P 1995 1.6 1.5 0,3 h0.3, v0.5 1.5 12 Gravel 27Dongjin China 89 W/P/I 1995 1.4 1.3 0.3+0.0023H 0,4 4-8 28 sandstone 1760 800

Jaraiz de la Vera Spain 46 S 1995Messochora Greece 135 P/I 1995 1.4 1.4 0.3+0.003H 0,5 0.7 50 LimestoneNamgang Korea ROK 34 1995 1.3 1.3 0,35

Pichi-Pic un-leufu Argentina 40 P 1995 1.5 1.5 0,3 0,35 4 Gravel, panel wall

Roseau Santa Lucia 40 W 1995 1.3 1.5 0,3 0,33 3.3 6.8 AndesiteSanta Juana Chile 110 W/I 1995 1.5 1.6 0.3+0.002H 0,3 3-5 Gravel, panel wall 390 160

Wananxi China 94 P 1995 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 18 Granite, porphry 1290 228Xiaolongtou China 36 1995Xiaomeisha China 49 W 1995 1.4 1.4 0,35 0,4 3-4 6 Granite 220 1,5

Babagon Malaysia 63 W 1996 1.3 1.6 0,3 3-5 sandstone, randomChalong China 39 I 1996 1.8 1.8 0,4 0,45 3-4 9 Gravel 370 138Douyan China 58 P 1996 1.4 1.6 0,3 h0.34, v0.52 4-5 19 Granite 520 98

Haichaoba China 57 I 1996 1.4 1.3-1.4 0,35 h 0.4, v 0.5 4-5 13 Granite 480 7Houay Ho Loas 85 P 1996 1.4 1.5 0,3 0,52 4-9 22 Sandstone 1250 595

Nanche China 64 I/P/F 1996 1.4 1.4 0.3-0.45 0,425 3.5-5.5 12 Sandstone 460 153Pingtan China 55 I/S 1996 390 11Shankou China 39 P/I 1996 1.4 1.4 0,3 0,4 3 9 Tuff 650 46

Xikou Upper China 38 P 1996 1.4 1.3-1.4 0,3 0,426 4 6 Conglomerate 140 1Yacambu Venezuela 162 W 1996 1.5 1.6 0.3+0.002H 0,4 Concrete 13 Gravel 435

damBadu China 58 I/W/F/P 1997 1.3 1.3 6 Tuff lava 840 32

Bastonia ? 110 1997 1.5 1.5 0.3+0.003H 0,5 4.6 30 AndesiteFrancis Creek Australia I 1997 1.3 1.3 0,3 3-5 Spillway overcrest

Lianghui China 35 W/I/F/P 1997 1.4 1.4 0,35 0,8 3.5-4.5 22 Panel wall, gravel 680 31Lianhua China 72 P/F/I 1997 1.4 1.4 0.3+0.003H h 0.4, v 0.5 4-6 75 Granite 4230 4180





Meixi China 38 I 1997 1.4 1.3 0,35 0,4 Panel wall 37 Panel wall, gravel 1200 265Rastolrita Romania 105 P/W 1997 1.5 1.5 0.3+0.003H 0,5 4.0-6.0 30 Andesite 3100 43

Tianhuangping China 95 P 1997 1.4 1.3 0.3+0.002H 0,4 4-6 21 Rhyolite, tuff lava 1420 9Xiaoshan China 86 P 1997 1.4 1.4 0.3+0.003H h0.37, v.4-.5 6-8 36 Andesite 1430 97

Xikou Lower China 43 P 1997 1.4 1.5, 1.6 0,3 0,426 4 11 Tuff 440 1Zeya China 79 W/F/P 1997 1.3 1.3 0,4 0,4 3.5-6 Tuff lava 1420 57

Baiyun China 120 P 1998 1.4 1.4 0.3+0.002H h 0.35, v 0.4 4-5 15 Limestone, 1700 360Cengang China 28 W/I 1998 1.4 1.4 0,35 0,4 3 11 Panel wall, tuff lava 310 6

Liangchahe China 43 I/F/P 1998 1.5 1.6 0,3 0.35-0.4 4-5 17 Gravel 510 63Caruachi Venezuela 80 P 1999 1,3 1,3 0,35 0,35 3 60 Granite, Gneiss 2000 4

Chakoukane Morocco 63 I 1999 1.6 1.6 Gravel panelwall 1800 50Daiqiad China 91 S/I/P 1999 1.5 1.7 0.3-0.5 0.3 2090 158

Dchar El Qued Morocco 101 I/P 1999 1.4 2.1 0.3+0.003H 0.3 4-5 Rockfill 2000 740Ita Brazil 125 P 1999 1.3 1.3 0.3+0.0025H 0.3H 0.4V 4-6 110 Basalt 9300 5100

Runcv Romania 90 W/P 1999 1.4 1.4 0.3+0.002H 0.45 4.0 26.2 Granite 1900 26Corrales Chile 70 I 2000 1.5 1.6 0.3-0.5 0.4 3-4 29 Gravel 1600 50Mohale Lesotho 145 I/P 2000 1.4 1.4 0.3+0.0035H 0.4 3+H/15 87 Basalt 7400 938Puclaro Chile 100 I 2000 1.5 1.6 0.3-0.45 0.3 3-4 87 Gravel 4780 200

Yang Yang Korea ROK 93 P 2000 1.4 1.4 0.35 5 GneissDim Turkey 135 I/P/W 2001 1.4 1.5 0.3+0.0035H 0.4 13 51 Schist 4093 250

Gordes Turkey 95 I/W 2001 1.4 1.5 0.35+0.003H 0.4 9 61 Limestone 4700 450Guasquitas Panama 49 P 2001 1.4 1.5 0.3 0.3 3 Gravel

Kurtun Turkey 133 P 2001 1.4 1.5 0.3+0.003H 0.4 10 35 Granodorite 3026 108Nam Ngum 3 Laos 220 P 2001 1.4 1.4 0.3+0.003H 0.3, 0.11 4-11 5 Sandstone,

Atasu Turkey 122 W/P 2002 1.4 1.5 0.3+0.0035H 0.4 12 45 Andesite, Basalt 3787 36Kwai Nai-Main Thailand 95 I 2002 1.4 1.4La Regadera II Colombia 90 W 2002 1.5 1.6 0.3+0.002H 0.3H 0.35V 3 Gravel

Machadinho Brazil 125 P 2002 1.3 1.3 0.3+0.0033H 0.3 3-6 93 Sandstone 6800Mukorsi Zimbabwe 89 I 2002 1.3 1.3 0.4 0.5 4+H/30 22.3 Gneiss 2440 1802Shanxi China 131 P 2002 1.4 1.4 0.3+0.003H 0.4 6-10 61 Rhyolite, gravel 5000 1922

Torata Peru 100 W 2002 1.3 1.3 0.3+0.002H 0.3H 0.35V 4Cercado Colombia 120 2003 1.4 1.4 0.3+0.002H 0.35H 0.4V 3-6 37 Vulcanite 2900 198





Dhauliganga India 50 H 2003 Gneisspanel cut off

Itatebi Brazil 100 2003 1.3 1.3 0.42 0.35H 0.4V 3-5 70 Gneiss, Diorite 3100 1650Mazar Equador 171 P 2003

Sogamoso Colombia 190 P 2004 1.4 1.4 0.3+0.002H 0.3 0.4 6-10 75 GravelTocoma Venezuela 40 P 2004 1.3 1.3 0.35 0.3H 0.35V 3 Gneiss

Baixi China 124 W/I/P UC 1.4 1.4 0.3+0.003H 0.4 5-8 48 Tuff lava 3600 168Sandstone

Bakun China 124 W/I/F/P UC 1.55 1.4 0.3+0.0035H 0.3, 0.4 4-7 79 Gravel, Granite 5500 182Bayibuxie China 35 I UC Gravel 200 4Chaishitan China 103 I/P UC 1,4 1,4 0.3+0.003H 6-7 38 Dolomite 2170 437Chusong China 40 P/I UC 1.8 1.3 0.3 0.4 Gravel 700 15

Daao China 90 UC 1.4 1.4 0.3-0.6 26 Sandstone 1450 278Dahe China 68 P/F UC 1.4 1.4 0,4 3-5 Limestone, slate 900 332

Daqiao China 91 W/I/P UC 1.5 1.7 0.3-0.5 0.3 6-9 30 Gravel 2090 658Douling China 89 P/I/W/F UC 1.4 1.6 32 Limestone, Phylite 2240 485Gaotang China 111 P UC 26 Granite 1950 96

Gudongkou China 120 I/F/P UC 1.4 1.5 0.3+0.003H h 0.4, v 0.5 4.5-10 Gravel, limestone 1900 138Heiquan China 124 W/I/P UC 1.55 1.4 0.3+0.0035H 0.3, 0.4 4-7 79 Gravel, gneiss 5500 182

Kalangguer China 62 P/F/W/I UC 1.5 1.4 0.3+0.003H h 0.4, v 0.5 5-6 36 Gravel, Andesite 1200 39Liangjiao China 55 UC 21 Granite 1110 210Motuola China 36 UC

Qiezishan China 107 I/P UC 1.4 1.4 0.3+0.003H 0.3, 0.4 5-7 Granite 1400 121Qinshan China 122 P UC 1.4 1.35 0.3+0.003H 0,5 5, 6, 8 42 Tuff 3100 265Sanchaxi China 89 UC 14 770 47

Sanguozhuang China 64 I/P/F UC 20 Basalt 800 15Shapulong China 65 P UC 1.3 1.3 0,4 4-5 7 Tuff lava 450 9Shedong China 50 UC 8Songshan China 79 P UC 1.4 1.4 0.3+0.003H 0,5 6-8 24 Andesite 1420 123Suojinshan China 62 UC 600 100Tanzitan China 62 UC 1.35 1.35 0,4 0,4 4 36 Sandstone, 630 12Tasite China 43 I UC 1.6 1.6 Panel wall, gravel 450 12





Tianshengqiao No.1 China 178 P/I/F UC 1.4 1.4 0.3+0.005H 0,4 4-9 156 Limestone 17 690 10 260Wuluwati China 135 F/I/P UC 1.6 1.6 0.3+0.003H h 0.4, v 0.5 6-10 76 Gravel, schist 6800 340Xiaoxikou China 68 I/P UC 1.4 1.3 0,4 20 Limestone 1110 66Yubeishan China 74 UC 38 890 860

Acena Spain 65 I UD 1.3 1.3 0.3+0.003H 0,4 3+H/15 GneissAgbulu Philippines 234 P UD 1.4 1.5 21 000 3981

Al Wehda Jordan 140 W/I UD 1.3 1.5 0.3+0.003H 0.5 BasaltAntamina Peru 115 Tailings UD 1.3 1.3 0.3 0.35 4 LimestoneArriaran Spain 50 UD 1.4 1.4Bakun Malaysia 205 P UD 1.4 1.4 0.3+0.003H 0.3 0.4 4-6 127 Greywacke, 17 000 43 800

Siltstone

Bocaina Brazil 80 P UD 1.3Canvelo Spain 35 UDCarcauz Spain 70 UD

Centianhe raised China 110 P UD 2500 1600Daliushu China 156 I/P UD 1.6 1.8 0.3-0.8 0.35 6-10 164 Sandstone 14 500 10 743Diguillin Chile I UDFenes Romania 40 W/F UD 1.6 1.5 n/a n/a Trench 5 Granite 245 6.5

Gongbaixia China 130 P UD 1.4 1.4 0.3+0.003H 0.4 4-8 46 Granite, Gravel 4550 550Goyeb Ethiopia 130 P UD

Hongjiadu China 182 P UD 1.4 1.4 0.3+0.003H 0.5 6-10 76 Limestone, 10 000 4590Sandstone

Ibba Yeder Spain 66 UD 1.35 1.5Jiemian China 126 P/I/F UD 58 Sandstone, 3420 1058

mudstoneJilingtai China 152 P UD 1.5 1.9 0.3+0.003H 0.5, 0.4 6-10 74 Tuff 9200 2440Jilintai Laos 152 UD 1.5 1.5 74 TuffJishixia China 100 P UD 1.5 1.55 0.3+0.003H 0.4, 0.5 4, 6, 7.4 Gravel, ballast 2880 264Kaliwa Philippines 100 UDPankou China 123 P UD 1.4 1.5 0.3+0.0038H 0.5 4-7.5 46 Limestone 3460 2460

Panshitou China 101 W/F/I/P UD 1.4 1.5 0.3-0.5 0.3, 0.4 75 Sandstone, shale 5290 679Poneasca Romania 52 W/P UD 1.3 1.4 0.3+0.001H 0,5 2.5 5.2 Limestone 1000 8Sanbanxi China 179 P UD 1.4 1.4 0.3+0.0035H 0.4 6-12 94 Sandstone 960 4170





Sancheng 1 Korea ROK 65 P UD 1.4 1.4 0.3+0.002HSancheng 2 Korea ROK 90 P UD 1.4 1.4 0.3+0.002HSanta Rita Brazil 85 P UD 1.3 1.3Shuanggou China 110 P UD 1.4 1.4 0.3+0.003H h0.3, v.4 3.5-5.5 41 Andesite, basalt 2580 391Shuibaya China 232 P UD 1.4 1.4 0.3+0.003H 0.4 4-10 Limestone 15 500 4700

Taia Romania 64 UD 1.65 1.55 Gallery 9.7 SchistTaian China 40 P UD 1.3 1.3

Tankeng China 161 P UD 1.4 1.4 0.3+0.003H 0.4 6-10 68 Tuff lava 10 000 3530Wawushan China 140 I/P UD 545

Xiangshuijian China 153 P UD 1.4 1.4 2570 17

Yaojiaping China 180 P UDYaoshui China 103 UD 1.4 1.55 29 1720 52

Yesa Spain 117 I/P UD 1.3 1.5Yutiao China 110 W/P/I UD 30 Sandstone 1630 95

Zipingpu China 159 P UD 1.4 1.5 0.3+0.003H 5, 8, 15 127 Sandstone 11 670 1080Andaqui Colombia 160 Z

Awonga Raised Australia 63 ZBabaquara Brazil 80 P Z 1.3 1.3 0.3Bajiaotan China 70 Z 1.4 1.4 Shale


Boon. Stage 2 Australia 73 ZCampos Novos Brazil 210 P ZCirata (Raised) Indonesia 140 P ZCuesta Blanca Argentina 80 Z 1.4 1.5 0.3+0.003H

Guizhou Horgjiadu China 182 P Z LimestoneHuallaga Peru 140 Z

Huangliao China 40 Z 1.4 1.4 0.25 0.35 3 2 Tuff lava,spillway over dam

Jurua Brazil 40 P Z 1.3 1.3 0.25Kaeng Krung Thailand 110 P/I Z 1.3 1.3-1.5 0.3


Los Molles Argentina 46 Z 1.5 1.5 0.3+0.003H 6 12 Gravel 730 20 000





Man.Cr.Raised Australia 105 W Z 1.5 1.6 0.3+0.003H 0.35 3, 4, 5 34 Siltstone/M'dez Morocco 97 I/P Z 1.8 1.6 0.3+0.003H 0.3 3-5 40 Gravel 1900 600

Merowe (Nile) Sudan 83 P Z 1.3 1.4 0.3+0.003H 0.3, 0.4 4-15 GraniteMurum Malaysia 141 P Z 1.4 1.4 0.3+0.003H 0.35 3-15 74 Greywacke, 6600 12 043

mudstoneNam Khek Thailand 125 P/I Z 1.4 1.5 0.4 4-7 59 Conglomerate,

sandstonePipay-Guazu 2 Argentina 73 Z 1.3 1.3 0.3+0.004H

Porce III Colombia 145 P ZQuimbo Colombia 150 P Z 1.5,1.6 Gravel

Tetelcingo Mexico 150 P Z 1.5 1.5 0.3+0.002HWest Seti Nepal 220 P Z 1.5 1.6 0.3+0.003H 0.4 4-11 Gravel 12 500 1604

Xe Kaman Laos 187 P Z 1.3 1.3 0.3+0.002H 0.35H 0.4V 4-9 84 Sandstone 9200 17 3302nd Stage 200 1.3 1.4 mine tailings dam


La Parota Mexico 162 P C 1.5 1.4 0.3+0.003H 4-8 170 Gravel, gneiss 12 000 6752Lungga Solomons CTa Seng Myanmar 162 P C

Xe Namnoy Laos 78 P CYedigaze Turkey 105 C



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